Thermoplastic elastomer composition and process for producing the same

ABSTRACT

A thermoplastic elastomer composition of the invention, formed by dynamically crosslinking a polymer composition including a rubber and an olefinic resin and having an average particle size of rubber particles within a specific range, shows an excellent balance of mechanical properties such as flexibility and elastic recovery, and a moldability. Also an inclusion of a (meth)acrylate resin and a hydrogenated diene polymer provides a composition particularly excellent in scratch resistance. Also an inclusion of a maleimide compound provides a composition particularly excellent in injection fusibility. Also an inclusion of an undenatured organopolysiloxane of a specific viscosity and a denatured organopolysiloxane provides a composition particularly excellent in initial slidability and durable slidability.

TECHNICAL FIELD

The present invention relates to a thermoplastic elastomer compositionand a method for producing the same. More specifically, it relates to athermoplastic elastomer composition having an excellent balance ofmechanical characteristics such as flexibility and elastic recovery, anda moldability, and a method for producing the same. It also relates to athermoplastic elastomer composition excellent in flexibility, scratchresistance, mechanical characteristics and rubber elasticity and amethod for producing the same. It further relates to a thermoplasticelastomer composition excellent in injection fusibility and a method forproducing the same. It further relates to a thermoplastic elastomercomposition excellent in initial slidability, durable slidability,abrasion resistance, thermal fusibility and moldability, and beingsatisfactory in external appearance and touch of a molded article, and amethod for producing the same.

BACKGROUND TECHNOLOGY

A thermoplastic elastomer composition, formed by a dynamically heattreating of a rubber and an olefinic resin in the presence of acrosslinking agent, does not require a vulcanizing step and can beeasily formed into a molded article by an ordinary molding method for athermoplastic resin, such as injection molding, profile extrusionmolding, calendering or blow molding.

However, such dynamically crosslinked olefinic thermoplastic elastomeris inferior in elastic recovering property to a vulcanized rubber. Forimproving such elastic recovering property, there have been investigatedan increase in the crosslinking density and a higher Mooney viscosity inthe rubber. These methods improve the elastic recovery but thethermoplastic elastomer composition loses fluidity significantly. Alsoin order to improve the moldability, there can be employed a method ofadding a peroxide-decomposable olefinic rubber, but such method isassociated with a drawback that the elastic recovering property isdeteriorated. It has thus not been easy, in the prior technologies, toobtain a thermoplastic elastomer composition in which the elasticrecovery and the moldability are well balanced.

Also in recent years, thermoplastic elastomers which are a rubber-likesoft material not requiring a vulcanizing process and having amoldability similar to that of thermoplastic resins are attractingattention and used in various fields such as automotive parts, parts forconsumer electric appliances, parts for medical and food instruments,electric wires, and household goods. In such thermoplastic elastomers,those of polyolefin type, polystyrene type, polyurethane type, polyestertype, polyvinyl chloride type or the like. have been developed andcommercialized. Among these, particularly useful are a blend employingan olefinic resin and an ethylene•α-olefine random copolymer rubber asprincipal raw materials, and an olefinic dynamically crosslinkedthermoplastic elastomer employing an olefinic resin and anethylene•α-olefine random copolymer rubber as principal raw materialsand partially crosslinked with a crosslinking agent. These materialshave excellent heat resistance, weather resistance, cold resistance andmoldability, and are relatively inexpensive. For these reasons, thesematerials are attracting attention, particularly in automotive parts orthe like, as a replacement of metal parts for the purpose of a weightreduction, a replacement for RIM urethane parts for the purposes of animprovement in the service life of the parts and for a cost reduction, areplacement for vulcanized rubber for the purposes of simplification ofworking process, recyclability and a cost reduction and a replacementfor soft polyvinyl chloride for the purpose of an improvement in theservice life and an improvement in contamination, and consumption ofthese materials is increasing year after year.

However the olefinic dynamically crosslinked thermoplastic elastomer isinferior in a surface scratch resistance (scratch resistance), and isstill insufficient for use in molded articles requiring scratchresistance, such as an inner panel or a surface material of a consolebox.

Also the olefinic dynamically crosslinked thermoplastic elastomer isexcellent in heat resistance, ozone resistance and weather resistance,also has a rubber elasticity similar to that of vulcanized rubber, andalso has a moldability almost comparable to olefinic thermoplasticresins such as polyethylene or polypropylene. Utilizing theseproperties, it is employed in molded products requiring rubberelasticity such as a bumper, an external lace, a window sealing gasket,a door sealing gasket, a trunk sealing gasket, a roof siderail, anemblem, an internal surface finishing material or the like. for anautomobile. It is also employed in various gaskets for construction use.Among these, the olefinic dynamically crosslinked thermoplasticelastomer used in the applications particularly requiring rubberelasticity such as automotive gaskets for window sealing, door sealing,trunk sealing or the like, and gaskets for construction purpose can beobtained by increasing the content of the ethylene•α-olefine copolymerrubber component in comparison with the olefinic dynamically crosslinkedthermoplastic elastomer employed in other applications.

However, the olefinic dynamically crosslinked thermoplastic elastomerobtained in this manner has a low fluidity at the molding, and it isdifficult to directly produce an automotive gasket or a constructiongasket of a complex shape by injection molding. On the other hand, aprior process for molding such gaskets is complex and requires a longwork time as explained in the following, and an improvement is stronglydesired for work saving and for improving productivity.

For molding a gasket, for example in case of ordinary vulcanized rubber,there has been employed a process of forming a linear portion of thegasket by a profile extrusion molding of unvulcanized rubber, thenvulcanizing the article produced by profile extrusion molding, andadding and vulcanizing a curved adjoining portion between ends of suchmolded articles in slit molds thereby forming a connecting part.However, such process requires the vulcanizing step twice. In order tosimplify such process and reduce the work time, there are conceived amethod of replacing the adjoining portion between the ends of theprofile extruded and vulcanized articles by an olefinic dynamicallycrosslinked thermoplastic elastomer not requiring vulcanization and amethod of replacing also the profile extruded articles of the linearportions with an olefinic dynamically crosslinked thermoplasticelastomer, and the former method is considered desirable practically. Insuch method of replacing the adjoining portion between the ends of theprofile extruded and vulcanized articles by the olefinic dynamicallycrosslinked thermoplastic elastomer, there is adopted a method ofplacing profile extruded articles in a split mold and injecting anolefinic dynamically crosslinked thermoplastic elastomer in an adjoiningportion thereby fusing the end portions. However, in most cases, it isdifficult to obtain a fusion with a practically acceptable adhesionstrength. For example, JP-B-61-53933 proposes a method, in mutuallyadjoining extrusion molded articles of an olefinic dynamicallycrosslinked thermoplastic elastomer, of preheating the articles to beadjoined thereby improving the adhesion strength. Also JP-A-59-221347proposes a method, in a similar adjoining, of employing an olefinicdynamically crosslinked thermoplastic elastomer containing crystallinepoly-1-butene thereby improving the adhesion strength even withoutpreheating. However, in these methods, a sufficient effect cannot beobtained particularly in case the member to be adjoined is olefinicvulcanized rubber. Consequently there is strongly desired a developmentof an olefinic composition thermoplastic elastomer composition showingan excellent injection fusibility for an olefinic vulcanized rubber andan olefinic dynamically crosslinked thermoplastic elastomer as thematerial to be adjoined.

Furthermore, the olefinic dynamically crosslinked thermoplasticelastomer, having a flexibility and excellent rubber-like properties andnot requiring a vulcanizing step, can produce a molded article by amolding method for ordinary thermoplastic resins such as injectionmolding, profile extrusion molding, calendering, or blow molding. Forthis reason, it is recently used increasingly, in view of energy saving,resource saving and recyclability, in automotive parts, industrialproducts, electric and electronic parts, construction materials or thelike. as a replacement for vulcanized rubber or vinyl chloride resin.

However, in automotive parts such as a glass run channel or a windowlace, it is associated with drawbacks of a low slidability to a windowpane and a low durability.

For improving the slidability, JP-A-2000-26668 discloses an olefinicthermoplastic elastomer composition prepared by addingorganopolysiloxane and an aliphatic amide to an olefinic dynamicallycrosslinked thermoplastic elastomer. Also JP-A-2000-143884 discloses anolefinic thermoplastic elastomer composition formed by addingacryl-denatured organopolysiloxane and a higher fatty acid or a higherfatty acid amide to an olefinic dynamically crosslinked thermoplasticelastomer or employing these in combination.

However, either composition shows an insufficient slidability, and alsohas a drawback that the appearance becomes defective because of bleedingout of aliphatic acid amide.

Furthermore, JP-A-2000-959000 discloses an olefinic thermoplasticelastomer formed by adding organopolysiloxane of a viscosity of 10 cStor higher but less than 10⁶ cSt, organopolysiloxane of a viscosity of10⁶ to 10⁸ cSt and a fluorinated polymer to an olefinic dynamicallycrosslinked thermoplastic elastomer.

However, though a high content of organopolysiloxane provides asatisfactory slidability, organopolysiloxane showing a low mutualsolubility with the olefinic dynamically crosslinked thermoplasticelastomer causes bleeding out, thereby providing an unpleasant stickyfeeling when the surface is touched, and there is strongly desired thedevelopment of an olefinic dynamically crosslinked thermoplasticelastomer free from bleeding-out phenomenon and showing excellentslidability.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of theaforementioned situation and is to provide a thermoplastic elastomercomposition having an excellent balance of mechanical properties such asflexibility and elastic recovery, and a moldability, and a method forproducing the same.

Another object of the invention is to provide a thermoplastic elastomercomposition having features of prior olefinic dynamically crosslinkedthermoplastic elastomers and excellent in a scratch resistance, and amethod for producing the same.

Still another object of the invention is to provide a thermoplasticelastomer composition having an excellent injection fusibility, showinga high adhesion strength to a member to be adhered constituted of anolefinic vulcanized rubber or a member to be adhered constituted of anolefinic dynamically crosslinked thermoplastic elastomer, and adaptedfor use requiring an improved surface scratch resistance andparticularly requiring thermal fusion, and a method for producing thesame.

Still another object of the invention is to provide a thermoplasticelastomer composition excellent in an initial slidability, a durableslidability, an abrasion resistance, a thermal fusibility and amoldability, and providing a satisfactory appearance and a satisfactorytouch in a molded article, and a method for producing the same.

The invention is summarized in the following:

-   1. A thermoplastic elastomer composition formed by dynamically heat    treating, in the presence of a crosslinking agent, a polymer    composition including a rubber and an olefinic resin;

wherein the rubber included in the thermoplastic elastomer compositionhas a gel fraction of 80% or higher, and rubber particles contained inthe thermoplastic elastomer composition has a number-averaged particlesize (dn) equal to or less than 3 μm and a ratio (dv/dn) of avolume-averaged particle size (dv) to the number-averaged particle size(dn) equal to or less than 1.5.

-   2. A thermoplastic elastomer composition according to the foregoing    1, wherein the gel fraction is 95% or higher and the dn is 2 μm or    less.-   3. A thermoplastic elastomer composition according to the foregoing    1, wherein, for a sum of the rubber and the olefinic resin taken as    100 parts by mass, the rubber is present at a level of 20 to 95    parts by mass, the olefinic resin is present at a level of 5 to 80    parts by mass, and the crosslinking agent is present at a level of    0.05 to 10 parts by mass.-   4. A thermoplastic elastomer composition according to the foregoing    1, wherein the rubber is an ethylene•α-olefin copolymer rubber, and    the ethylene•α-olefin copolymer rubber has a limiting viscosity [η]    of 2.0 to 6.8 dl/g when measured at 135° C. in decaline as a    solvent.-   5. A thermoplastic elastomer composition formed by dynamically heat    treating, in the presence of a crosslinking agent, a polymer    composition including a rubber, an olefinic resin, a (meth)acrylate    resin and a hydrogenated diene polymer.-   6. A thermoplastic elastomer composition according to the foregoing    5, wherein the hydrogenated diene polymer is formed by hydrogenation    of a copolymer having a polymer block principally formed by a vinyl    aromatic unit and a polymer block principally formed by a conjugate    diene unit.-   7. A thermoplastic elastomer composition according to the foregoing    5, wherein, for a sum of the rubber, the olefinic resin, the    (meth)acrylate resin and the hydrogenated diene polymer taken as 100    mass %, the rubber is present at a level of 20 to 95 mass %, the    olefinic resin is present at a level of 3 to 70 mass %, the    (meth)acrylate resin is present at a level of 1 to 20 mass %, and    the hydrogenated diene polymer is present at a level of 1 to 10 mass    %.-   8. A thermoplastic elastomer composition according to the foregoing    5, wherein the rubber is an ethylene•α-olefin copolymer rubber, and    the ethylene•α-olefin copolymer rubber has a limiting viscosity [η]    of 2.0 to 6.8 dl/g when measured at 135° C. in decaline as a    solvent.-   9. A thermoplastic elastomer composition formed by dynamically heat    treating, in the presence of a crosslinking agent, a polymer    composition including a rubber, an olefinic resin, a softening agent    and a maleimide compound, in which, for a sum of the rubber, the    olefinic resin and the softening agent taken as 100 mass %, the    olefinic resin is present at a level of 5 to 36 mass %, and for a    sum of the rubber, the olefinic resin and the softening agent taken    as 100 parts by mass, the maleimide compound is present at a level    of 0.3 to 10 parts by mass.-   10. A thermoplastic elastomer composition according to the foregoing    9, wherein, for a sum of the rubber, the olefinic resin and the    softening agent taken as 100 mass %, the rubber is present at a    level of 20 to 85 mass % and the softening agent is present at a    level of 10 to 75 mass %.-   11. A thermoplastic elastomer composition characterized by being    formed by dynamically heat treating, in the presence of a    crosslinking agent, a polymer composition including a rubber, an    olefinic resin, a softening agent, a (meth)acrylate resin, and a    maleimide compound, wherein for a sum of the rubber, the olefinic    resin and the softening agent taken as 100 parts by mass, the    maleimide compound is present at a level of 0.3 to 10 parts by mass    and the (meth)acrylate resin is present at a level of 1 to 30 parts    by mass.-   12. A thermoplastic elastomer composition according to the foregoing    11, further including a hydrogenated diene polymer, wherein the    hydrogenated diene polymer is present at a level of 0.1 to 1 in a    mass ratio to the (meth))acrylate resin.-   13. A thermoplastic elastomer composition characterized by being    formed by dynamically heat treating, in the presence of a    crosslinking agent, a polymer composition including an    ethylene•α-olefin copolymer rubber which has a limiting viscosity    [η] of 2.0 to 6.8 dl/g when measured at 135° C. in decaline as a    solvent, an olefinic resin, a softening agent and a maleimide    compound, wherein, for a sum of the rubber, the olefinic resin and    the softening agent taken as 100 parts by mass, the maleimide    compound is present at a level of 0.3 to 10 parts by mass.-   14. A thermoplastic elastomer composition formed by dynamically heat    treating, in the presence of a crosslinking agent, a polymer    composition including a rubber, an olefinic resin, a softening    agent, a low-viscosity undenatured organopolysiloxane having a    viscosity measured at 25° C. according to JIS K2283 less than 10,000    cSt, a high-viscosity undenatured organopolysiloxane having a    viscosity measured at 25° C. according to JIS K2283 equal to or    higher than 10,000 cSt, and a denatured organopolysiloxane.-   15. A thermoplastic elastomer composition according to the foregoing    14, wherein, for a sum of the rubber, the olefinic resin and the    softening agent taken as 100 parts by mass, the rubber is present at    a level of 20 to 69 parts by mass, the olefinic resin is present at    a level of 1 to 50 parts by mass, and the softening agent is present    at a level of 20 to 79 parts by mass.-   16. A thermoplastic elastomer composition according to the foregoing    14, wherein, for a sum of the rubber, the olefinic resin and the    softening agent taken as 100 parts by mass, the low-viscosity    undenatured organopolysiloxane is present at a level of 1 to 10    parts by mass, the high-viscosity undenatured organopolysiloxane is    present at a level of 1 to 10 parts by mass, and the denatured    organopolysiloxane is present at a level of 0.2 to 20 mass %.-   17. A thermoplastic elastomer composition formed by dynamically heat    treating, in the presence of a crosslinking agent, a polymer    composition including an oil-extended rubber including a rubber and    a softening agent in which, for a sum of the rubber and the    softening agent taken as 100 mass %, the rubber is present at a    level of 30 to 70 mass % and the softening agent is present at a    level of 30 to 70 mass %, an olefinic resin, a post-addition    softening agent which is added when required, an undenatured    organopolysiloxane having a viscosity measured at 25° C. according    to JIS K2283 less than 10,000 cSt, an undenatured organopolysiloxane    having a viscosity measured at 25° C. according to JIS K2283 equal    to or higher than 10,000 cSt, and a denatured organopolysiloxane.-   18. A thermoplastic elastomer composition according to the foregoing    17, wherein, for a sum of the oil-extended rubber, the olefinic    resin and the post-addition softening agent taken as 100 parts by    mass, the oil-extended rubber is present at a level of 30 to 99    parts by mass, the olefinic resin is present at a level of 1 to 50    parts by mass, and the post-addition softening agent is present at a    level of 50 parts by mass or less (including 0 parts by mass).-   19. A thermoplastic elastomer composition according to the foregoing    17, wherein, for a sum of the oil-extended rubber, the olefinic    resin and the post-addition softening agent taken as 100 parts by    mass, the low-viscosity undenatured organopolysiloxane is present at    a level of 1 to 10 parts by mass, the high-viscosity undenatured    organopolysiloxane is present at a level of 1 to 10 parts by mass,    and the denatured organopolysiloxane is present at a level of 0.2 to    20 mass %.-   20. A thermoplastic elastomer composition according to the foregoing    14 or 17, wherein the rubber is an ethylene•α-olefin copolymer    rubber, and the ethylene•α-olefin copolymer rubber has a limiting    viscosity [η] of 2.0 to 6.8 dl/g when measured at 135° C. in    decaline as a solvent.-   21. A method for producing a thermoplastic elastomer composition    characterized in melt kneading a polymer composition including a    rubber and an olefinic resin, and other additives excluding a    crosslinking agent or a part of the crosslinking agent, or a polymer    composition including a rubber and an olefinic resin, a crosslinking    agent and other additives, in a closed kneader to obtain a melted    blended substance, and then supplying the melted blended substance    or the melted blended substance and the crosslinking agent to a    continuous extruder thereby executing dynamically heat-treating.-   22. A method for producing a thermoplastic elastomer composition    characterized in adding a crosslinking agent to a polymer    composition containing a rubber and an olefinic resin, and then    supplying the mixture to plural connected continuous kneaders    thereby executing dynamically heat-treating.-   23. A method for producing a thermoplastic elastomer composition    characterized in supplying a polymer composition including a rubber    and an olefinic resin to an extrusion apparatus constituted of a    serial connection of an upstream continuous two-shaft kneader with    different rotating directions and a downstream two-shaft extruder    with a same rotating direction, from a raw material introducing part    of the continuous two-shaft kneader with different rotating    directions thereby kneading the polymer composition in the    continuous two-shaft kneader with different rotating directions, and    supplying the kneaded substance to the two-shaft extruder with a    same rotating direction with a temperature of the kneaded substance    maintained at 250° C. or less at an exit of the continuous two-shaft    kneader with different rotating directions thereby executing a    dynamic crosslinking.-   24. A method for producing a thermoplastic elastomer composition    characterized in supplying a polymer composition including a rubber,    an olefinic resin and an organic peroxide having a 1-minute    half-period temperature T_(h) (° C.) within a range of    T_(m)≦T_(h)≦T_(m)+50 (° C.) in which T_(m) is a melting point (° C.)    of the olefinic resin, to an extrusion apparatus constituted of a    serial connection of an upstream continuous two-shaft kneader with    different rotating directions and a downstream two-shaft extruder    with a same rotating direction, from a raw material introducing part    of the continuous two-shaft kneader with different rotating    directions thereby kneading the polymer composition in the    continuous two-shaft kneader with different rotating directions, and    supplying the kneaded substance to the two-shaft extruder with a    same rotating direction with a temperature (t_(a)) of the kneaded    substance maintained within a range of T_(h)−30≦t_(a)≦T_(h)+30 (°    C.) at an exit of the continuous two-shaft kneader with different    rotating directions thereby executing a dynamic crosslinking.

The present invention provides following effects.

According to the invention, a polymer composition formed by a rubber, anolefinic resin or the like. is dynamically crosslinked to obtain athermoplastic elastomer composition having an excellent balance ofmechanical properties such as flexiblity and elastic recovery, and amoldability. Such composition enables easy working with injectionmolding, extrusion molding, blow molding, compression molding, vacuummolding, laminate molding or calender molding.

Also the olefinic thermoplastic elastomer composition can be madeparticularly excellent in scratch resistance, and is useful inapplications in which the prior olefinic thermoplastic elastomer isemployed, particularly in molded parts such as automotive indoor andoutdoor parts such as a weather strip, a sponge or a lace, or a housingfor a consumer electric appliances, and a leather sheet productrequiring a scratch resistance.

It can also be made excellent in an injection fusibility, and is widelyapplicable not only to various composite worked products having aninjection fused portion but also to ordinary worked products. It isuseful, for example, to automotive indoor and outdoor surface materialssuch as a bumper, an external lace, a window sealing gasket, a doorsealing gasket, a trunk sealing gasket, a roof side rail, or an emblem,a sealing material or an indoor or outdoor surface material for anaircraft or a ship, a sealing material, an indoor or outdoor surfacematerial or a waterproof sheet for construction or building, a sealingmaterial for machinery and apparatuses, a packing or a housing forconsumer electric appliances, household goods and sporting goods.

It can further be made a thermoplastic elastomer composition excellentin initial slidability, durabable slidability and abrasion resistanceand satisfactory in external appearance and touch of the molded article,and is useful for automotive parts such as a glass run channel or awindow lace.

DISCLOSURE OF THE INVENTION

[1] A Thermoplastic Elastomer Composition Including Rubber Particles ofa Specific Particle Size

The thermoplastic elastomer composition of the present invention ischaracterized in being formed by dynamically heat-treating, in thepresence of a crosslinking agent, of a polymer composition including arubber and an olefinic resin. In particular, it is a thermoplasticelastomer composition formed by dynamically heat treating, in thepresence of a crosslinking agent, a polymer composition including arubber and an olefinic resin (such composition being hereinafter calleda “specific-sized rubber particle-containing composition [A]”), whereinthe rubber included in the specific-sized rubber particle-containingcomposition [A] has a gel fraction of 80% or higher, and rubberparticles contained in the specific-sized rubber particle-containingcomposition [A] has a number-averaged particle size (dn) equal to orless than 3 μm and a ratio (dv/dn) of a volume-averaged particle size(dv) to the number-averaged particle size (dn) equal to or less than1.5.

(1) Rubber

1) Type of Rubber

The rubber is not particularly restricted, and can for example beisoprene rubber, butadiene rubber, styrene-butadiene rubber, naturalrubber, chloroprene rubber, butyl rubber, nitrile rubber, hydrogenatednitrile rubber, norbornene rubber, ethylene•α-olefinic copolymer rubber,acryl rubber, ethylene-acrylate rubber, fluorinated rubber,chlorosulfonated polyethylene rubber, epichlorohydrine rubber, siliconerubber, urethane rubber, polysulfide rubber, phosphazene rubber, or1,2-polybutadiene. Among these, ethylene•α-olefinic copolymer rubber ispreferable. Such rubber may be employed singly, or in a combination oftwo or more kinds.

2) Ethylene•α-olefinic Copolymer Rubber

The ethylene•α-olefinic copolymer rubber (hereinafter also simply called“copolymer rubber”) includes an ethylene unit and an α-olefin unit,other than ethylene, as principal constituent units. In case the entirecopolymer rubber is taken as 100 mol %, it is preferred that a sum ofthe ethylene unit and the α-olefin unit represents 90 mol % or higher.

α-olefin to be employed in the preparation of the copolymer rubber canbe an α-olefin with 3 to 12 carbon atoms such as propene (hereinaftercalled “propylene”), 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene,3-methyl-1-pentene, 4-methyl-1-pentene, 3-ethyl-1-pentene, 1-octene,1-decene or 1-undecene. Among these, propylene and 1-butene arepreferred. These may be employed singly or in a combination of two ormore kinds.

As another monomer, there can be employed a non-conjugate diene.Examples of such non-conjugate diene include 1,4-pentadiene,1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene,3,6-dimethyl-1,7-octadiene, 4,5-dimethyl-1,7-octadiene,5-methyl-1,8-nonadiene, dicyclopentadiene, 5-ethylidene-2-norbornene,5-vinyl-2-norbornene, and 2,5-norbornadiene. Among these,dicyclopentadiene and 5-ethylidene-2-norbornene are particularlypreferred. These may be employed singly or in a combination of two ormore kinds.

As the copolymer rubber, there is preferred an ethylene•α-olefinicbinary copolymer rubber or an ethylene•α-olefinic•non-conjugate dieneternary copolymer rubber. As the ethylene•α-olefinic binary copolymerrubber, there is often employed ethylene•propylene copolymer rubber andethylene•1-butene copolymer rubber. In such copolymer rubber, anethylene content, for the entire copolymer rubber taken as 100 mol %, ispreferably from 50 to 95 mol %, particularly preferably from 60 to 90mol %.

Also as the ethylene•α-olefinic•non-conjugate diene ternary copolymerrubber, there is often employed ethylene•propylene•dicyclopentadieneternary copolymer rubber, ethylene•propylene•5-ethylidene-2-norborneneternary copolymer rubber, ethylene•1-butene•dicyclopentadiene ternarycopolymer rubber, or ethylene•1-butene•5-ethylidene-2-norbornene ternarycopolymer rubber. In such copolymer rubber, an ethylene content, for asum of the ethylene unit and the propylene unit or the 1-butene unittaken as 100 mol %, is preferably from 50 to 95 mol %, particularlypreferably from 60 to 90 mol %. Also content of dicyclopentadiene or5-ethylidene-2-norbornene, for a sum of the ethylene unit and thepropylene unit or the 1-butene unit taken as 100 mol %, is preferablyfrom 3 to 10 mol %, particularly preferably from 3 to 8 mol %.

A content of the ethylene unit less than 50 mol % in the copolymerrubber tends to reduce the crosslinking efficiency (particularly in casean organic peroxide is used as a crosslinking agent), possibly beingunable to obtain a copolymer rubber with sufficient physical properties.On the other hand, an ethylene content exceeding 95 mol % mayundesirably reduce the flexibility of the copolymer rubber.

Also the ethylene•α-olefinic copolymer rubber preferably has a limitingviscosity [η] measured at 135° C. in decaline equal to or higher than1.0 dl/g, preferably from 2.0 to 6.8 dl/g, particularly preferably from3.5 to 6.8 dl/g and further preferably from 4.5 to 6.0 dl/g. A limitingviscosity less than 2.0 dl/g may reduce the elastic recovery. On theother hand, a limiting viscosity exceeding 6.8 dl/g may undesirablyreduce the workability of the molded article.

As the copolymer rubber, in addition to the ethylene•α-olefinic binarycopolymer rubber and the ethylene•α-olefinic-non-conjugate diene ternarycopolymer rubber, there may also be employed a halogenated copolymerrubber formed by substituting a part of hydrogen atoms of such copolymerrubbers with a halogen atom such as a chlorine atom or a bromine atom.It is also possible to employ a graft copolymer rubber formed by graftpolymerizing a monomer for example a (meth)acrylic acid derivative suchas vinyl chloride, vinyl acetate, (meth)acrylic acid, methyl(meth)acrylate, glycidyl (meth)acrylate or (meth)acrylamide, a maleicacid derivative such as maleic acid, maleic anhydride, maleimide, ordimethyl maleate, or a conjugate diene such as butadiene, isoprene orchloroprene with the binary copolymer rubber, the ternary copolymerrubber or the halogenated copolymer rubber. Each of such halogenatedcopolymer rubber and graft copolymer rubber may be employed singly or ina combination of two or more kinds, or the halogenated copolymer rubberand the graft copolymer rubber may be employed in combination.

The copolymer rubber can be prepared by a polymerization method under amedium or low pressure, for example a method of polymerization in thepresence of a catalyst constituted of a Ziegler-Natta catalyst, asoluble vanadium compound and an organic aluminum compound added in asolvent, by supplying ethylene, α-olefin and a non-conjugate diene incase of a ternary copolymer rubber, and hydrogen as a molecular weightregulating agent if necessary. Such polymerization can be executed forexample by a gaseous method such as a fluidized bed method or anagitated bed method, or a liquid method such as a slurry method or asolution method.

As the soluble vanadium compound, there is preferably employed areaction product of VOCl₃ and/or VCl₄ and an alcohol. Examples of suchalcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol,sec-butanol, t-butanol, n-hexanol, n-octanol, 2-ethylhexanol, n-decanoland n-dodecanol, among which preferred is an alcohol with 3 to 8 carbonatoms.

Also as the organic aluminum compound, there can be employed, forexample, triethyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum,diethyl aluminum monochloride, diisobutyl aluminum monochloride, ethylaluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminumdichloride, butyl aluminum dichloride, or methyl aluminoxane which is areaction product of trimethyl aluminum and water. Among these, there isparticularly preferred ethyl aluminum sesquichloride, butyl aluminumsesquichloride, a mixture of ethyl aluminum sesquichloride andtriisobutyl aluminum, or a mixture of triisobutyl aluminum and butylaluminum sesquichloride.

Also as the solvent, a hydrocarbon solvent is preferable, and n-pentane,n-hexane, n-heptane, n-octane, isooctane or cyclohexane is particularlypreferable. These may be employed singly or in a combination of two ormore kinds.

A content of rubber included in the polymer composition, for a sum ofrubber and olefinic resin taken as 100 parts by mass, is preferably 20to 95 parts by mass, particularly preferably 40 to 94 parts by mass, andfurther preferably 60 to 93 parts by mass. A rubber content less than 20parts by mass tends to reduce flexibility and elasticity of thespecific-sized rubber particle-containing composition [A]. On the otherhand, a content exceeding 95 parts by mass decreases fluidity of thespecific-sized rubber particle-containing composition [A], therebysignificantly deteriorating the moldability.

3) Gel Fraction of Rubber

The rubber included in the specific-sized rubber particle-containingcomposition [A] has a gel fraction of 80% or higher, preferably 90% orhigher, particularly preferably 95% or higher, further preferably 96% orhigher and most preferably 97% or higher. From the standpoint of themechanical strength of the specific-sized rubber particle-containingcomposition [A], such gel fraction is preferably 95% or higher, and agel fraction less than 95% results in a decrease in the mechanicalstrength and also in an insufficient rubber elasticity. The gel fractionis measured in the following manner.

About 200 mg of a specific-sized rubber particle-containing composition[A] are weighed and cut into small pieces. Then the small pieces areimmersed for 48 hours at 23° C. in 100 ml of cyclohexane in a closedcontainer. Then the small pieces are taken out on a filter paper, andare dried under a reduced pressure for 1 hour at 105° C. in a vacuumdryer. From a mass of the dried residue, (1) a mass of acyclohexane-insoluble portion (filler, pigment or the like.) other thanthe rubber and the olefinic resin, and (2) a mass of the olefinic resincontained in the sample before immersion in cyclohexane, are deducted toobtain a “corrected final mass (p)”.

On the other hand, from a mass of the sample, (3) a mass of acyclohexane-soluble portion (for example softening agent) other than therubber and the olefinic resin, (1) a mass of a cyclohexane-insolubleportion (filler, pigment or the like.) other than the rubber and theolefinic resin, and (4) a mass of the olefinic resin, are deducted toobtain a “corrected initial mass (q)”.

The gel fraction (cyclohexane-insoluble portion) is calculated from afollowing equation:gel fraction(mass %)=[{corrected final mass(p)}÷{corrected initialmass(q)}]×100.

4) Rubber Content

A content of the rubber is, for a sum of the rubber and the olefinicresin taken as 100 parts by mass, preferably 20 to 95 parts by mass,particularly preferably 40 to 94 parts by mass and further preferably 60to 93 parts by mass. A rubber content less than 20 parts by mass tendsto reduce the flexibility and the elasticity of the thermoplasticelastomer. On the other hand, a content exceeding 95 parts by mass mayreduce the fluidity of the thermoplastic elastomer composition, therebyundesirably resulting in an insufficient moldability.

5) Crosslinked Rubber Particles

Crosslinked rubber particles in the specific-sized rubberparticle-containing composition [A] can be observed under a transmissionelectron microscope (hereinafter represented as TEM). In thespecific-sized rubber particle-containing composition [A], anumber-averaged particle size dn of the rubber particles, calculatedfrom areas of the crosslinked rubber particles obtained from an imageanalysis of a TEM photograph showing the crosslinked rubber particles,is 3 μm or less, preferably 2 μm or less, particularly preferably 1.4 μmor less and further preferably 1.0 μm or less, and a ratio dv/dn of avolume-averaged particle size dv and a number-averaged particle size dn,determined from the number-averaged particle size dn, is 1.5 or less,preferably 1.4 or less, and particularly preferably 1.3 or less. Withinsuch range, there can be obtained a specific-sized rubberparticle-containing composition [A] having desired satisfactory rubberelasticity, mechanical properties and moldability. Even in case thedv/dn ratio is 1.5 or less, a number-averaged particle size exceeding 2μm, particularly 3 μm, tends to deteriorate the moldability. Also evenin case the number-averaged particle size is 3 μm or less, particularly2 μm or less, a dv/dn ratio exceeding 1.5 tends to deteriorate themechanical properties. The dv/dn ratio of 1 indicates that the particlesare in a uniform state with an aligned size, and the ratio larger than 1indicates that the particle are more uneven with more unaligned sizes.

For observation of the specific-sized rubber particle-containingcomposition [A] under the TEM, the specific-sized rubberparticle-containing composition [A] is at first formed into a thin sliceby a frozen microtome method and is dyed with a dyeing agent such asruthenium tetroxide, osmium tetroxide, chlorosulfonic acid, uranylacetate, phosphotungstenic acid, iodide ion or trifluoroacetic acid. Inselecting the dyeing agent, it is necessary to select an optimum dyeingagent according to the kind of the functional group present in themolecule of the specific-sized rubber particle-containing composition[A] to be observed. As the dyeing agent, ruthenium tetroxide or osmiumtetroxide is optimum.

Then the dyed slice of the specific-sized rubber particle-containingcomposition [A] is photographed with a magnification of 2000 times undera TEM.

The number-averaged particle size and the volume-averaged particle sizecan be determined by an image analysis of a TEM photograph, and therecan be utilized an image analysis software such as Image-Pro Plus Ver.4.0 for Windows (manufactured by MediaCybernetics (U.S.A.), sold byPlanetron Hanbai Co.).

The number-averaged particle size dn and the volume-averaged particlesize dv can be obtained by determining areas of the crosslinked rubberparticles by the image analysis and executing calculations according tofollowing equations. More specifically, there can be utilized acalculating method described in J. Macromol. Sci. Phys., B38(5 & 6),527(1999):

1) A calculation formula of a diameter (dn_(j)) of a circle convertedfrom an area of a crosslinked rubber particle obtained from the imageanalysis of TEM photograph:

${dn}_{j} = \sqrt{\frac{4}{\pi} \cdot A_{particle}}$A: area of crosslinked rubber particle obtained from image analysis ofTEM photograph

2) A calculation formula of a number-averaged particle size (dn) ofcrosslinked rubber particles:

$d_{n} = \frac{\sum\limits_{i}^{\;}\; d_{n_{j}}}{n}$

3) A calculation formula of a volume-averaged particle size (dv) ofcrosslinked rubber particles:

$d_{v} = \sqrt{\frac{\sum\limits_{i}^{\;}\; d_{n_{j}}^{3}}{n}}$(2) Olefinic Resin

As the olefinic resin to be employed in the specific-sized rubberparticle-containing composition [A] of the invention, there can beemployed a crystalline olefinic resin and/or an amorphous olefinicresin.

1) Crystalline Olefinic Resin

The crystalline olefinic resin is not particularly limited, however itpreferably includes an α-olefin as a principal constituent unit. Morespecifically, it preferably includes, for the entire olefinic resintaken as 100 mol %, an α-olefinic unit by 80 molt or more, particularlypreferably 90 molt or more.

The crystalline olefinic resin can be a single polymer of α-olefin, or acopolymer of two or more α-olefins. It can also be a copolymer of anα-olefin and another monomer. It can further be a mixture of two or morecrystalline olefinic resins and/or copolymer resins.

For use in the preparation of the crystalline olefinic resin, there ispreferred an α-olefin with 3 or more carbon atoms, and an α-olefin with3 to 12 carbon atoms described in the aforementioned copolymer rubber ismore preferable. In case the crystalline olefinic resin is a copolymerwith ethylene, an ethylene content, for the entire copolymer taken as100 mol %, is preferably 40 molt or less, particularly 20 molt or less.

In case the crystalline olefinic resin is a copolymer, the copolymer canbe a random copolymer or a block copolymer. However, in order to obtaina random copolymer having a crystallinity explained in the following,taking the entire random copolymer as 100 molt, a total content ofconstituent units excluding α-olefin is preferably made 15 molt or less,particularly preferably 10 molt or less. In case of being a blockcopolymer, taking the entire block copolymer as 100 mol %, a totalcontent of constituent units excluding α-olefin is preferably made 40mol % or less, particularly preferably 20 mol % or less.

The random copolymer can be prepared by a method similar to that for theaforementioned copolymer rubber. Also a block copolymer can be preparedfor example by a living polymerization utilizing a Ziegler-Nattacatalyst.

The crystalline olefinic resin preferably has a crystallinity, measuredby an X-ray diffraction, of 50% or higher, particularly preferably 53%or higher and further preferably 55% or higher. Also, the crystallinityis closely related with a density. For example, in case ofpolypropylene, an α-crystal (monoclinic) has a density of about 0.936g/cm³, a smectic microcrystal (pseudo hexagonal) has a density of about0.886 g/cm³, and an amorphous (atactic) component has a density of about0.850 g/cm³. Also in case of poly-1-butene, an isotactic crystal has adensity of about 0.91 g/cm³, and an amorphous component (atactic) has adensity of about 0.87 g/cm³. Consequently, in order to obtain acrystalline polymer with a crystallinity of 50% or higher, there ispreferred a density of 0.89 g/cm³ or higher, particularly 0.90 to 0.94g/cm³. A crystallinity less than 50% or a density less than 0.89 g/cm³tends to deteriorate the heat resistance and the strength of thespecific-sized rubber particle-containing composition [A].

Also in the crystalline olefinic resin, a maximum peak temperaturemeasured by a scanning differential calorimeter, or a melting point(hereinafter represented simply as “T_(m)”), is variable depending onthe monomer to be employed, however it is preferably 100° C. or higher,particularly preferably 120° C. or higher. A T_(m) less than 100° C. maynot provide a heat resistance and a strength in a sufficient level.

Also the crystalline olefinic resin preferably has a melt flow rate(hereinafter simply represented as “MFR”), measured at a temperature of230° C. and under a load of 2.16 kg, of 0.1 to 100 g/10 minutes,particularly preferably 0.5 to 80 g/10 minutes. An MFR less than 0.1g/10 minutes tends to provide a kneading workability and an extrusionworkability of an insufficient level. On the other hand, an MFRexceeding 100 g/10 minutes tends to deteriorate the strength.

Consequently, as the crystalline olefinic resin, it is particularlypreferably to employ polypropylene and/or a copolymer of propylene andethylene, having a crystallinity of 50% or higher, a density of 0.89g/cm³ or higher, an ethylene unit content of 20 mol % or less, a T_(m)of 100° C. or higher, an MFR of 0.1 to 100 g/10 minutes and a meltingpoint of 140 to 170° C.

2) Amorphous Olefinic Resin

The amorphous olefinic resin is not particularly limited, however itpreferably includes an α-olefin as a principal constituent unit. Morespecifically, it preferably includes, taking the entire amorphousolefinic resin as 100 mol %, an α-olefinic unit by 50 molt or more,particularly preferably 60 molt or more.

The amorphous olefinic resin can be a single polymer of α-olefin, or acopolymer of two or more α-olefins. It can also be a copolymer of anα-olefin and another monomer. It can further be a mixture of two or morepolymers and/or copolymers.

For use in the preparation of the amorphous olefinic resin, there ispreferred an α-olefin with 3 or more carbon atoms, and an α-olefin with3 to 12 carbon atoms described in the aforementioned copolymer rubber ismore preferable.

Examples of the amorphous olefinic resin include a single polymer suchas atactic polypropylene, or atactic poly-1-butene, a copolymer ofpropylene (preferably containing the propylene unit by 50 molt or more)with another α-olefin such as ethylene, 1-butene, 1-pentene, 1-hexene,4-methyl-1-pentene, 1-octene or 1-decene, and a copolymer of 1-butene(preferably containing the 1-butene unit by 50 molt or more) withanother α-olefin such as ethylene, propylene, 1-pentene, 1-hexene,4-methyl-1-pentene, 1-octene or 1-decene.

In case the amorphous olefinic resin is a copolymer, the copolymer canbe a random copolymer or a block copolymer. However, in case of blockcopolymer, an α-olefin unit such as a propylene unit or a 1-butene unitconstituting a principal unit in the copolymer has to be bonded by anatactic structure. Also in case of an amorphous olefinic resin formed bya copolymer of an α-olefin with 3 or more carbon atoms and ethylene, anα-olefin content, taking the entire copolymer as 100 mol %, ispreferably 50 mol % or higher, particularly preferably 60 to 100 mol %.

As the amorphous olefinic resin, there is particularly preferred atacticpolypropylene (with a propylene content of 50 mol % or higher), acopolymer of propylene (50 mol % or higher) and ethylene, or a copolymerof propylene (50 mol % or higher) and 1-butene.

The atactic polypropylene can be obtained as a by-product of crystallinepolypropylene. Also, atactic polypropylene or atactic poly-1-butene canbe obtained by a polymerization utilizing a catalyst constituted of acombination of a zirconocene compound and methyl alminoxane. The randomcopolymer can be prepared by a method similar to that for theaforementioned copolymer rubber, and the block copolymer can be preparedfor example by a living polymerization utilizing a Ziegler-Nattacatalyst.

The amorphous olefinic resin preferably has a melt viscosity at 190° C.of 50 Pa·s or less, particularly preferably 0.1 to 30 Pa·s and furtherpreferably 0.2 to 20 Pa·s. A melt viscosity exceeding 50 Pa·s tends toreduce an adhesion strength with a member to be adhered, in case of aninjection fusion with vulcanized rubber or a thermoplastic elastomer.

Also the amorphous olefinic resin preferably has a crystallinity,measured by an X-ray diffraction, less than 50%, particularly preferably30% or less and further preferably 20% or less. Also, as in the case ofthe crystalline olefinic resin, the crystallinity is closely relatedwith a density, which is preferably 0.85 to 0.89 g/cm³, particularly0.85 to 0.88 g/cm³. A crystallinity exceeding 50% and/or a densityexceeding 0.89 g/cm³ tends to reduce an adhesion strength with a memberto be adhered, in case of an injection fusion with vulcanized rubber ora thermoplastic elastomer.

Also the amorphous olefinic resin preferably has a number-averagedmolecular weight (M_(n)) of 1,000 to 20,000, particularly preferably1,500 to 15,000.

As the olefinic resin, the crystalline olefinic resin and the amorphousolefinic resin may be employed in combination, or either one may beemployed alone.

3) Content of Olefinic Resin

A content of the olefinic resin, for a sum of the rubber and theolefinic resin taken as 100 parts by mass, is preferably 5 to 80 partsby mass, particularly preferably 6 to 60 parts by mass and furtherpreferably 7 to 40 parts by mass. In case the content of the olefinicresin is less than 5 parts by mass, a phase structure (morphology) ofthe specific-sized rubber particle-containing composition [A] may notassume a satisfactory sea-island structure (olefinic resin constitutinga sea (matrix) and crosslinked rubber constituting an island (domain))which is a feature of the dynamically crosslinked thermoplasticelastomer, thereby deteriorating the moldability and the mechanicalproperties. On the other hand, a content exceeding 80 parts by massundesirably reduces the flexibility and the rubber elasticity of thespecific-sized rubber particle-containing composition [A].

(3) Softening Agent

The specific-sized rubber particle-containing composition [A] usuallyincludes a softening agent. Such softening agent is not particularlyrestricted, and can be, for example, (1) a carboxylic acid-basedsoftening agent such as stearic acid or lauric acid, (2) a vegetableoil-based softening agent such as palm oil, cotton seed oil, linseedoil, or rape oil, (3) pine tar, (4) a factice such as white factice,black factice or brown factice, (5) a mineral oil type softening agentsuch as a paraffinic mineral oil, a naphthenic mineral oil or anaromatic mineral oil, (6), an ester softening agent such as dibutylphthalate, dioctyl phthalate, dioctyl adipate, dibutyl glycol adipate,dibutyl carbitol adipate, dioctyl sebacate, dibutyl sebacate, tricresylphosphate, cresylphenyl phosphate, tributyl phosphate, trioctylphosphate, tributoxyethyl phosphate, a polyether plasticizer, or anadipate polyester, and (7) a hydrocarbon softening agent such as apolybutene agent or a polybutadiene agent. Among these, a minetal oilsoftening agent is preferable, and a mineral oil type softening agentwith a weight average molecular weight of 300 to 2,000, particularly 500to 1,500 is particularly preferable. The softening agent for rubberbased on mineral oil hydrocarbons is generally a mixture of an aromaticring component, a naphthene ring component and a paraffin chaincomponent, and is classified into a paraffinic oil in which a number ofcarbon atoms of the paraffin chain represents 50% or more of totalnumber of carbon atoms, a naphthenic oil in which a number of carbonatoms of the naphthene ring represents 30 to 45% of total number ofcarbon atoms, and an aromatic oil in which a number of carbon atoms ofthe aromatic ring represents 30% or more of total number of carbonatoms. In the invention, there is preferred a paraffinic oil, morepreferably a hydrogenated paraffinic oil. Also the mineral oilhydrocarbon preferably has a dynamic viscosity at 40° C. of 20 to 800cSt, particularly preferably 50 to 600 cSt, and a fluidity point of −40to 0° C., particulary preferably −30 to 0° C. Such hydrocarbon may beemployed singly or in a combination of two or more kinds.

A content of the softening agent can be made 200 parts by mass or lesswith respect to 100 parts by mass of rubber, preferably 180 parts bymass or less, particularly preferably 150 parts by mass or less andfurther preferably 100 parts by mass or less. A softening agent contentexceeding 150 parts by mass, particularly 200 parts by mass, tends tocause a bleeding out of the softening agent from specific-sized rubberparticle-containing composition [A] or a deterioration of the mechanicalproperties and the rubber elasticity. In case of employing anoil-extended rubber, the softening agent may be that contained in theoil-extended rubber only, or may be added as a post-addition.

The specific-sized rubber particle-containing composition [A] can beeasily worked for example by injection molding, extrusion molding, blowmolding, compression molding, vacuum molding, laminate molding orcalender molding, and can provide a thermoplatic elastomer moldedarticle excellent in rubber elasticity and mechanical properties.

[2] A Thermoplastic Elastomer Composition Including Acrylate Resin

Another thermoplastic elastomer composition of the invention(hereinafter called “acrylate resin-containing composition [B]”) ischaracterized in being formed by dynamically heat-treating, in thepresence of a crosslinking agent, of a polymer composition including arubber, an olefinic resin, a (meth)acrylate resin and a hydrogenateddiene polymer.

In the acrylate resin-containing composition [B], the rubber and theolefinic resin can be those described in the foregoing. The rubber isparticularly preferably an ethylene•α-olefin random copolymer rubber. Asthe olefinic resin, there can be employed a crystalline olefinic resinand/or an amorphous olefinic resin. As the crystalline olefinic resin,polypropylene or a propylene-ethylene copolymer is particularlypreferable. Also as the amorphous olefinic resin, there is particularlypreferred atactic polypropylene (with a propylene content of 50 mol % orhigher), a copolymer of propylene (50 mol % or higher) and ethylene, ora copolymer of propylene (50 mol % or higher) and 1-butene.

In the acrylate resin-containing composition [B], the rubber, for a sumof the rubber, the olefinic resin, the (meth)acrylate resin and thehydrogenated diene polymer taken as 100 mass %, is preferably presentwithin a range of 20 to 95 mass %, particularly preferably 30 to 90 mass%. Also the olefinic resin is preferably present within a range of 3 to70 mass %, particularly preferably 5 to 60 mass %. A rubber content lessthan 20 mass % reduces the flexibility and the rubber elasticity of theacrylate resin-containing composition [B]. On the other hand, a contentexceeding 95 mass % reduces the fluidity of the acrylateresin-containing composition [B], thereby significantly deterioratingthe moldability. Also in case the content of the olefinic resin is lessthan 3 mass %, a phase structure (morphology) of the acrylateresin-containing composition [B] may not assume a satisfactorysea-island structure (olefinic resin constituting a sea (matrix) andcrosslinked rubber constituting an island (domain)) which is a featureof the dynamically crosslinked thermoplastic elastomer, therebydeteriorating the moldability and the mechanical properties. On theother hand, a content exceeding 70 mass % undesirably reduces theflexibility and the rubber elasticity of the acrylate resin-containingcomposition [B].

The acrylate resin-containing composition [B] usually includes anaforementioned softening agent. A content of the softening agent can bemade 200 parts by mass or less with respect to 100 parts by mass ofrubber, preferably 180 parts by mass or less, particularly preferably150 parts by mass or less and further preferably 100 parts by mass orless. A softening agent content exceeding 150 parts by mass,particularly 200 parts by mass, tends to cause a bleeding out of thesoftening agent from the acrylate resin-containing composition [B] or adeterioration of the mechanical properties and the rubber elasticity. Incase of employing an oil-extended rubber, the softening agent may bethat contained in the oil-extended rubber only, or may be added as apost-addition.

(1) (Meth)acrylate Resin

As the (meth)acrylate resin, there can be employed a polymer of vinylmonomers principally constituted of a monomer having an acryl group or amethacryl group. A monomer having an acryl group or a methacryl groupmeans a monomer having at least an acryl group or a methacryl group, andexamples include an acrylate alkyl ester such as methyl acrylate, ethylacrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate,t-butyl acrylate, s-butyl acrylate, 2-methylbutyl acrylate,3-methylbutyl acrylate, n-hexyl acrylate, n-heptyl acrylate, n-octylacrylate, or 2-ethylhexyl acrylate; a diacrylate ester such as ethyleneglycol diacrylate, 1,2-propylene glycol diacrylate, 1,3-propylene glycoldiacrylate, 1,2-butylene glycol diacrylate, 1,3-butylene glycoldiacrylate, or 1,4-butylene glycol diacrylate; a methacrylate alkylester such as methyl methacrylate, ethyl methacrylate, n-propylmethacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butylmethacrylate, s-butyl methacrylate, 2-methylbutyl methacrylate,3-methylbutyl methacrylate, n-hexyl methacrylate, n-heptyl methacrylate,n-octyl methacrylate, or 2-ethylhexyl methacrylate; and a dimethacrylatealkyl ester such as 1,2-propylene glycol dimethacrylate, 1,3-propyleneglycol dimethacrylate, 1,2-butylene glycol dimethacrylate, 1,3-butyleneglycol dimethacrylate, or 1,4-butylene glycol dimethacrylate.

Among the (meth)acrylate resins, a homopolymer methyl methacrylate or acopolymer formed by copolymerizing methyl methacrylate as a principalcomponent and another with a small amount of another monomer ispreferable. Such another monomer can be, for example, acrylic acid; anacylic acid metal salt; an acrylate ester such as methyl acrylate, ethylacrylate, n-butyl acrylate, s-butyl acrylate, t-butyl acrylate or2-ethylhexyl acrylate; methacrylic acid, a methacrylic acid metal salt;a methacrylate ester such as ethyl methacrylate, n-butyl methacrylate,s-butyl methacrylate, t-butyl methacrylate, 2-hydroxyethyl methacrylate,glycidyl methacrylate, or cyclohexyl methacrylate; an acetate ester suchas vinyl acetate; an aromatic vinyl compound such as styrene orα-methylstyrene; maleic anhydride, a maleic acid monoalkyl ester, amaleic acid dialkyl ester, or a maleimide such as N-phenylmaleimide.

The copolymer is not particularly limited to a type, and can be a randomcopolymer, a block copolymer such as of diblock, triblock, multiblock,or combtooth-shaped block type, or a multi-stage block copolymer. Alsothe (meth)acrylate resin is not particularly limited in its structure,and can be any of a linear type, a ramified type or a multi-layeredtype.

An MFR of the (meth)acrylate resin, measured at a temperature of 230° C.and under a load of 3.8 kgs is not particularly restricted, however itis preferably 0.1 to 100 g/10 minutes, particularly preferably 0.5 to 80g/10 minutes.

The acrylate resin-containing composition [B] preferably has a(meth)acrylate resin content of 1 to 20 mass %, particularly preferably5 to 15 mass %. A content less than 1 mass % deteriorates the scratchresistance of the acrylate resin-containing composition [B]. On theother hand, a content exceeding 20 mass % undesirably reduces theflexibility and the rubber elasticity of the acrylate resin-containingcomposition [B].

(2) Hydrogenated Diene Polymer

Examples of the hydrogenated diene polymer include hydrogenated productsof diene polymers such as a homopolymer of a conjugate diene monomer, arandom copolymer of a conjugate diene monomer and a vinyl aromaticmonomer, a block copolymer formed by polymer blocks of a vinyl aromaticmonomer and polymer blocks of a conjugate diene monomer, a blockcopolymer formed by polymer blocks of a vinyl aromatic monomer andrandom copolymer blocks of a conjugate diene monomer and a vinylaromatic monomer, a block copolymer formed by polymer blocks of aconjugate diene monomer and copolymer blocks of a conjugate dienemonomer and a vinyl aromatic monomer, a block copolymer formed bypolymer blocks of a conjugate diene monomer and tapered blocks of avinyl aromatic monomer and a conjugate diene monomer in which the vinylaromatic monomer increases gradually, a block copolymer formed by randomcopolymer blocks of a conjugate diene monomer and a vinyl aromaticmonomer and tabered blocks of a vinyl aromatic monomer and a conjugatediene monomer in which the vinyl aromatic monomer increases gradually,and a block copolymer formed by polybutadiene blocks with vinyl bondsrepresenting 30 mass % or less and polymer blocks of a conjugate dienemonomer with vinyl bonds representing more than 30 mass % (such polymerprior to hydrogenation being also called “pre-hydrogenation polymers”).

Among these hydrogenated diene polymers, there is preferred ahydrogenated product of a conjugate diene polymer having a polymer block(A) principally constituted of a vinyl aromatic monomer and a polymerblock (B) principally constituted of a conjugate diene monomer,particularly a hydrogenated product of a conjugate diene polymer havinga following block structure.

The polymer block (A) has a structure of a homopolymer of a vinylaromatic monomer or a copolymer of a vinyl aromatic monomer unitcontaining a vinyl aromatic monomer in excess of 50 mass %, preferablyin excess of 70 mass %, and a copolymerizable another monomer,preferably a conjugate diene monomer, and the polymer block (B) has astructure of a homopolymer of a conjugate diene monomer or a copolymerthereof copolymerized with another monomer such as a vinyl aromaticmonomer in an amount of 5 mass % or less, and the block copolymer has ablock structure of (A-B)n-A type (n being an integer from 1 to 10) or(A-B)m type (m being an integer from 2 to 10). The block A at an end mayhave a short block B. Also there can be employed a structure of[(A-B)n]m-M type (M represents a coupling agent residue such as Si orSn; m is a valence number of the coupling agent residue and is aninteger from 2 to 4; and n is an integer from 1 to 10, preferably 1 or2).

Such block copolymer may have plural kinds of the polymer block (A)and/or the polymer block (B), for example an A₁-B-A₂ type or anA₁-B₁-A₂-B₂ type. Monomer units constituting each of the blocks A₁ andA₂ may be same or different. Also the blocks B₁ and B₂ may be same ordifferent in the weight average molecular weight.

Examples of the vinyl aromatic monomer to be employed in the preparationof the pre-hydrogenation polymer include styrene, α-methylstyrene,p-methylstyrene, t-butylstyrene, divinylbenzene,N,N-dimethyl-p-aminoethylstyrene, 2,4-dimethylstyrene,N,N-diethyl-p-aminoethylstyrene, 2,4-dimethylstyrene, vinylnaphthaleneand vinylanthracene, among which styrene and α-methylstyrene arepreferred. These may be employed singly or in a combination of two ormore kinds.

Also examples of the conjugate diene monomer to be employed in thepreparation of the pre-hydrogenation polymer include 1,3-butadiene,isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene,2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-dimethyl-1,3-octadiene andchloroprene, among which preferred are 1,3-butadiene and isoprene. Thesemay be employed singly or in a combination of two or more kinds.

In the polymer block A, another monomer copolymerizable with the vinylaromatic monomer is principally an aforementioned conjugate dienemonomer, particularly preferably 1,3-butadiene or isoprene.

In the preparation of the pre-hydrogenation polymer, the conjugate dienemonomer and the vinyl aromatic monomer have a composition ratio(conjugate diene monomer/vinyl aromatic monomer) preferably within arange of 95/5 to 40/60 in mass ratio, more preferably 93/7 to 45/55.

In the conjugate diene unit of the pre-hydrogenation polymer, a vinylbond content (proportion of 1,2- and 3,4-vinyl bonds in the conjugatediene unit of the pre-hydrogenation polymer) is not particularlyrestricted, however it is preferably 50 to 85%, particularly preferably60 to 85%.

In such hydrogenated diene polymer, double bonds contained in theconjugate diene unit of the pre-hydrogenation polymer and derived fromthe conjugate diene are preferably saturated by 80% or more,particularly preferably 90% or more. A proportion of saturation lessthan 80% deteriorates the weather resistance or the like. Also thehydrogenated diene polymer has a weight average molecular weight of5,000 to 1,000,000, preferably 10,000 to 500,000.

The acrylate resin-containing composition [B] has a content of thehydrogenated diene polymer of 1 to 10 mass %, particularly preferably 2to 9 mass %. A content less than 1 mass % decreases a mutual solubilityof rubber, particularly ethylene•α-olefin copolymer rubber with olefinicresin and (meth)acrylate resin, thereby deteriorating the mechanicalproperties. On the other hand, a content exceeding 20 mass % undesirablyreduces the flexibility and the rubber elasticity of the acrylateresin-containing composition [B].

The acrylate resin-containing composition [B] has flexibility andexcellent scratch resistance and moldability, and can be widely employedin applications in which olefinic thermoplastic elastomers have beenutilized, for example automotive external and internal surface materialssuch as a bumper, an external lace, a window sealing gasket, a doorsealing gasket, a trunk sealing gasket, a roofside rail, an emblem, aninner panel or a console box, a leather sheet requiring a scratchresistance such as a weather strip, sealants or internal/externalsurface materials for aircraft and ship, sealants, internal/externalsurface materials or waterproof sheet materials for construction andbuilding, sealants for general machinery and apparatus, a packing or ahousing for consumer electric appliances, parts for medical equipment,electric wires, household goods, sporting goods or the like.

[3] A Thermoplastic Elastomer Composition Including a Maleimide Compound

Another thermoplastic elastomer composition of the invention(hereinafter called “maleimide compound-containing composition [C]”) ischaracterized in being formed by dynamically heat-treating, in thepresence of a crosslinking agent, of a polymer composition including arubber, an olefinic resin, a softening agent and a maleimide compound,in which, for a sum of said rubber, said olefinic resin and saidsoftening agent taken as 100 mass %, said olefinic resin is present at alevel of 5 to 36 mass %, and for a sum of the rubber, the olefinic resinand the softening agent taken as 100 parts by mass, the maleimidecompound is present at a level of 0.3 to 10 parts by mass.

In the maleimide compound-containing composition [C], the rubber and theolefinic resin can be those described in the foregoing. The rubber isparticularly preferably an ethylene•α-olefin random copolymer rubber. Asthe olefinic resin, there can be employed a crystalline olefinic resinand/or an amorphous olefinic resin. As the crystalline olefinic resin,polypropylene or a propylene-ethylene copolymer is particularlypreferable. Also as the amorphous olefinic resin, there is particularlypreferred atactic polypropylene (with a propylene content of 50 mol % orhigher), a copolymer of propylene (50 mol % or higher) and ethylene, ora copolymer of propylene (50 mol % or higher) and 1-butene.

In the maleimide compound-containing composition [C], for a sum of therubber, the olefinic resin and the softening agent taken as 100 mass %,the rubber is preferably present within a range of 20 to 85 mass %,particularly preferably 30 to 80 mass %. Also the olefinic resin ispreferably present within a range of 5 to 36 mass %, particularlypreferably 10 to 36 mass %. A rubber content less than 20 mass % reducesthe flexibility and the rubber elasticity of the maleimidecompound-containing composition [C]. On the other hand, a contentexceeding 85 mass % reduces the fluidity of the maleimidecompound-containing composition [C], thereby significantly deterioratingthe moldability. Also in case a content of the olefinic resin is lessthan 5 mass %, a phase structure (morphology) of the maleimidecompound-containing composition [C] may not assume a satisfactorysea-island structure (olefinic resin constituting a sea (matrix) andcrosslinked rubber constituting an island (domain)) which is a featureof the dynamically crosslinked thermoplastic elastomer, therebydeteriorating the moldability and the mechanical properties. On theother hand, a excessive content undesirably reduces the flexibility andthe rubber elasticity of the maleimide compound-containing composition[C].

The maleimide compound-containing composition [C] usually includes anaforementioned softening agent. A content of the softening agent, for asum of the rubber, the olefinic resin and the softening agent taken as100 mass %, is 10 to 75 mass %, preferably 20 to 60 mass %. A softeningagent content less than 10 mass % results in an insufficient moldabilityof the maleimide compound-containing composition [C]. On the other hand,a content exceeding 75 mass % deteriorates the rubber elasticity and themechanical properties. In case of employing an oil-extended rubber, thesoftening agent may be that contained in the oil-extended rubber only,or may be added as a post-addition.

In the maleimide compound-containing composition [C], the polymercomposition may further include a (meth)acrylate resin. The(meth)acrylate resin can be that described in the foregoing. Also, for asum of rubber, olefinic resin and softening agent taken as 100 parts bymass, the (meth)acrylate resin is present at a level of 1 to 30 parts bymass, particularly preferably 5 to 15 parts by mass. A content of the(meth)acrylate resin less than 1 part by mass results in an insufficientscratch resistance of the maleimide compound-containing composition [C].On the other hand, a content exceeding 30 parts by mass undesirablyreduces the flexibility and the rubber elasticity of the maleimidecompound-containing composition [C].

In the maleimide compound-containing composition [C], the polymercomposition may further include a hydrogenated diene polymer in additionto the (meth)acrylate resin. The hydrogenated diene polymer can be thatdescribed in the foregoing. A content of the hydrogenated diene polymer,with respect to the (meth)acrylate resin, is preferably 0.1 to 1 in massratio, particularly preferably 0.3 to 0.7. A mass ratio less than 0.1decreases a mutual solubility of rubber, particularly ethylene•α-olefinrandom copolymer rubber with olefinic resin and (meth)acrylate resin,thereby deteriorating the mechanical properties. On the other hand, amass ratio exceeding 1 undesirably reduces the flexibility and therubber elasticity of the maleimide compound-containing composition [C].

(1) Maleimide Compound

The maleimide compound functions as a crosslinking agent, particularlyas an auxiliary crosslinking agent in case of dynamically heat-treatingwith an organic peroxide. The maleimide compound can be N,N′-m-phenylenebismaleimide or N,N′-toluylene bismaleimide, and there is preferredN,N′-m-phenylene bismaleimide (CAS: 3006-93-7).

A content of the maleimide compound, for a sum of the rubber, theolefinic resin and the softening agent taken as 100 parts by mass, is0.3 to 10 parts by mass, preferably 0.4 to 8 parts by mass andparticularly preferably 0.5 to 5 parts by mass. A content of themaleimide compound less than 0.3 parts by mass may be unable to providea maleimide compound-containing composition [C] excellent in injectionfusibility and elastic recovery in an injection fused portion. On theother hand, a content exceeding 10 parts by mass may result in anexcessively high crosslinking degree, thereby deteriorating themoldability or the injection fusibility.

The maleimide compound-containing composition [C], having an excellentinjection fusibility, can be utilized in a thermoplastic elastomermolded article formed as an injection fused composite with an olefinicvulcanized rubber such as ethylene-propylene rubber,ethylene-propylene-diene rubber, ethylene-butene rubber, orethylene-butene-diene rubber; a vulcanized rubber such asethylene-acrylate rubber, chlorinated polyethylene, chlorosulfonatedpolyethylene, styrene-butadiene rubber, nitrile rubber, chloroprenerubber, acryl rubber, or urethane rubber; or a thermoplastic elastomersuch as an olefinic thermoplastic elastomer, a polyester thermoplasticelastomer, a polyurethane thermoplastic elastomer, or polyamidethermoplastic elastomer. As an adhered member, an olefinic vulcanizedrubber or an olefinic thermoplastic elastomer is particularly preferred.

-   [4] A Thermoplastic Elastomer Composition Including Polysiloxane

Another thermoplastic elastomer composition of the invention(hereinafter called a “polysiloxane-containing composition [D]”) ischaracterized in being formed by dynamically heat-treating, in thepresence of a crosslinking agent, of a polymer composition including arubber, a softening agent, an olefinic resin, a low-viscosityundenatured organopolysiloxane having a viscosity measured at 25° C.according to JIS K2283 less than 10,000 cSt, a high-viscosityundenatured organopolysiloxane having a viscosity measured at 25° C.according to JIS K2283 equal to or higher than 10,000 cSt, and adenatured organopolysiloxane.

In the polysiloxane-containing composition [D], the rubber and theolefinic resin can be those described in the foregoing. The rubber isparticularly preferably an ethylene•α-olefin copolymer rubber. As theolefinic resin, there can be employed a crystalline olefinic resinand/or an amorphous olefinic resin. As the crystalline olefinic resin,polypropylene or a propylene-ethylene copolymer is particularlypreferable. Also as the amorphous olefinic resin, there is particularlypreferred atactic polypropylene (with a propylene content of 50 mol % orhigher), a copolymer of propylene (50 mol % or higher) and ethylene, ora copolymer of propylene (50 mol % or higher) and 1-butene.

In the polysiloxane-containing composition [D], for a sum of the rubber,the olefinic resin and the softening agent taken as 100 parts by mass,the rubber is preferably present within a range of 20 to 69 parts bymass, particularly preferably 23 to 65 parts by mass and furtherpreferably 25 to 60 parts by mass. Also the olefinic resin is preferablypresent within a range of 1 to 50 parts by mass, particularly preferably2 to 45 parts by mass and further preferably 5 to 40 parts by mass. Arubber content less than 20 parts by mass may reduce the flexibility andthe rubber elasticity of the polysiloxane-containing composition [D]. Onthe other hand, a content exceeding 69 parts by mass reduces thefluidity of the polysiloxane-containing composition [D], therebysignificantly deteriorating the moldability. Also in case a content ofthe olefinic resin is less than 1 part by mass, a phase structure(morphology) of the polysiloxane-containing composition [D] may notassume a satisfactory sea-island structure (olefinic resin constitutinga sea (matrix) and crosslinked rubber constituting an island (domain))which is a feature of the dynamically crosslinked thermoplasticelastomer, thereby deteriorating the moldability and the mechanicalproperties. On the other hand, a content exceeding 50 parts by massundesirably reduces the flexibility and the rubber elasticity of thepolysiloxane-containing composition [D].

The polysiloxane-containing composition [D] usually includes anaforementioned softening agent. A content of the softening agent, for asum of the rubber, the olefinic resin and the softening agent taken as100 parts by mass, is preferably 20 to 79 parts by mass, particularlypreferably 25 to 75 parts by mass and further preferably 25 to 70 partsby mass. A softening agent content less than 20 parts by mass results inan insufficient fluidity of the polysiloxane-containing composition [D].On the other hand, a content exceeding 79 parts by mass may result in aninsufficient dispersion of the rubber and the olefinic resin atkneading, and tends to reduce the rubber elasticity also. In case ofemploying an oil-extended rubber, the softening agent may be thatcontained in the oil-extended rubber only, or may be added as apost-addition.

The polysiloxane-containing composition [D] can also be obtained bydynamically heat-treating, in the presence of a crosslinking agent, of apolymer composition including an oil-extended rubber which contains arubber and a softening agent, and in which, for a sum of the rubber andthe softening agent taken as 100 mass %, the rubber is present at alevel of 30 to 70 mass % and the softening agent is present at a levelof 30 to 70 mass %, an olefinic resin, an undenatured organopolysiloxanehaving a viscosity measured at 25° C. according to JIS K2283 less than10,000 cSt, an undenatured organopolysiloxane having a viscositymeasured at 25° C. according to JIS K2283 equal to or higher than 10,000cSt, and a denatured organopolysiloxane.

Also in such polysiloxane-containing composition [D] utilizing theoil-extended rubber, the rubber and the olefinic resin can be thosedescribed in the foregoing. The rubber is particularly preferably anethylene•α-olefin copolymer rubber. As the olefinic resin, there can beemployed a crystalline olefinic resin and/or an amorphous olefinicresin. As the crystalline olefinic resin, polypropylene or apropylene-ethylene copolymer is particularly preferable. Also as theamorphous olefinic resin, there is particularly preferred atacticpolypropylene (with a propylene content of 50 mol % or higher), acopolymer of propylene (50 mol % or higher) and ethylene, or a copolymerof propylene (50 mol % or higher) and 1-butene.

Also for a sum of the rubber and the softening agent constituting theoil-extended rubber taken as 100 mass %, a content each is 30 to 70 mass%, preferably 35 to 65 mass % and particularly preferably 40 to 60 mass%. In case a content of the rubber is less than 30 mass % or a contentof the softening agent exceeds 70 mass %, the polysiloxane-containingcomposition [D] may show a bleeding out of the softening agent or adeterioration in the mechanical properties and the rubber elasticity. Onthe other hand, in case a content of the rubber exceeds 70 mass % or acontent of the softening agent is less than 30 mass %, the moldabilityof the polysiloxane-containing composition [D] may be deteriorated. Asthe softening agent, there can be utilized those explained in theforegoing, without particular limitation.

In the polysiloxane-containing composition [D], a softening agent may befurther included by a post-addition, if necessary. Such post-addedsoftening agent, for a sum of the oil-extended rubber, the olefinicresin and the post-added softening agent taken as 100 parts by mass, ispreferably used in an amount of 50 parts by mass or less, particularly45 parts by mass or less and further preferably 40 parts by mass orless. A content exceeding 50 parts by mass may result in an insufficientdispersion of the rubber and the olefinic resin at kneading, and tendsto reduce the rubber elasticity also. As the post-added softening agent,there can be utilized those explained in the foregoing, withoutparticular limitation.

In such polysiloxane-containing composition [D], for a sum of theoil-extended rubber, the olefinic resin and the post-added softeningagent taken as 100 parts by mass, the oil-extended rubber is preferablypresent within a range of 30 to 99 parts by mass, particularlypreferably 35 to 97 parts by mass and further preferably 40 to 95 partsby mass. Also the olefinic resin is preferably present within a range of1 to 50 parts by mass, particularly preferably 2 to 45 parts by mass andfurther preferably 5 to 40 parts by mass. A rubber content less than 30parts by mass may reduce the flexibility of the polysiloxane-containingcomposition [D]. On the other hand, a content exceeding 99 parts by massreduces the fluidity of the polysiloxane-containing composition [D],thereby significantly deteriorating the moldability. Also in case acontent of the olefinic resin is less than 1 part by mass, a phasestructure (morphology) of the polysiloxane-containing composition [D]may not assume a satisfactory sea-island structure (olefinic resinconstituting a sea (matrix) and crosslinked rubber constituting anisland (domain)) which is a feature of the dynamically crosslinkedthermoplastic elastomer, thereby deteriorating the moldability and themechanical properties. On the other hand, a content exceeding 50 partsby mass undesirably reduces the flexibility and the rubber elasticity ofthe polysiloxane-containing composition [D].

(1) Low-viscosity or High-viscosity Undenatured Organopolysiloxane

The low-viscosity or high-viscosity undenatured organopolysiloxane isnot particularly limited. The undenatured organopolysiloxane can be, forexample, dimethylpolysiloxane, methylphenylpolysiloxane,fluoropolysiloxane, tetramethyltetraphenylpolysiloxane, ormethylhydrogen polysiloxane, among which dimethylpolysiloxane ispreferred. Also the low-viscosity undenatured organopolysiloxane and thehigh-viscosity undenatured organopolysiloxane may be a same compound ormay be different.

1) Low-viscosity Undenatured Organopolysiloxane

The low-viscosity undenatured organopolysiloxane has a viscosity at 25°C. as defined by JIS K2283 less than 10,000 cSt, preferably less than7,000 cSt and more preferably less than 5,000 cSt.

Also a content of the low-viscosity undenatured organopolysiloxane, fora sum of the oil-extended rubber, the olefinic resin and the post-addedsoftening agent taken as 100 parts by mass, is preferably 1 to 10 partsby mass, particularly preferably 1 to 8 parts by mass and furtherpreferably 1 to 5 parts by mass. However, a low-viscosity undenaturedorganopolysiloxane having a viscosity at 25° C. as defined by JIS K2283less than 10,000 cSt, in case employed singly, tends to bleed out fromthe polysiloxane-containing composition [D].

2) High-viscosity Undenatured Organopolysiloxane

The high-viscosity undenatured organopolysiloxane has a viscosity at 25°C. as defined by JIS K2283 equal to or higher than 10,000 cSt,preferably 10,000 to 1,000,000 cSt and more preferably 10,000 to 100,000cSt.

A content of the high-viscosity undenatured organopolysiloxane, for asum of the oil-extended rubber, the olefinic resin and the post-addedsoftening agent taken as 100 parts by mass, is preferably 1 to 10 partsby mass, particularly preferably 1 to 8 parts by mass and furtherpreferably 1 to 5 parts by mass. However, a high-viscosityorganopolysiloxane having a viscosity at 25° C. as defined by JIS K2283equal to or higher than 10,000 cSt, in case employed singly, tends toresult in an undesirably insufficient slidability.

A combined use of the low-viscosity undenatured organopolysiloxanehaving a viscosity at 25° C. as defined by JIS K2283 less than 10,000cSt and the high-viscosity undenatured organopolysiloxane having aviscosity equal to or higher than 10,000 cSt significantly improves theslidability. As to preferable contents of these, the low-viscosityundenatured organopolysiloxane is employed in 1 to 10 parts by masswhile the high-viscosity undenatured organopolysiloxane is employed in 1to 10 parts by mass, and more preferably the low-viscosity undenaturedorganopolysiloxane is employed in 1 to 5 parts by mass while thehigh-viscosity undenatured organopolysiloxane is employed in 1 to 5parts by mass.

(2) Denatured Organopolysiloxane

The denatured organopolysiloxane is not particularly restricted withinorganopolysiloxanes chemically modified with a functional group, such asacryl-denatured, epoxy-denatured, alky-denatured, amino-denatured,carboxyl-denatured, alcohol-denatured, fluorine-denatured,alkylallylpolyether-denatured, or epoxypolyether-denatured. Among these,an acryl-denatured organopolysiloxane is preferable, and particularlypreferred is a graft polymer of organopolysiloxane with an acrylic acidester or a mixture of acrylic acid and a copolymerizable monomer.

The acrylic acid ester graft polymerizable with organopolysiloxane canbe an alkyl acrylate such methyl acrylate, ethyl acrylate, propylacrylate, butyl acrylate, hexyl acrylate, pentyl acrylate, octylacrylate, 2-ethylhexyl acrylate, lauryl acrylate, or stearyl acrylate;an alkoxyalkyl acrylate such as methoxyethyl acrylate, or butoxyethylacrylate; cyclohexyl acrylate; phenyl acrylate; or benzyl acrylate, andthese may be employed singly or in a combination of two or more kinds.

Also the monomer copolymerizable with the acrylic acid ester can be ahydroxyl-containing unsaturated monomer such as 2-hydroxyethyl(meth)acrylate or 2-hydroxypropyl (meth)acrylate. These may be employedsingly or in a combination of two or more kinds.

At the graft polymerization, a proportion of organopolysiloxane and anacrylic acid ester or a monomer copolymerizable with the acrylic acidester is preferably, in a mass ratio of [organopolysiloxane/acrylic acidester or monomer copolymerizable with acrylic acid ester], within arange from 9/1 to 1/9, more preferably 8/2 to 2/8. Examples of theacryl-denatured organopolysiloxane include “X-22-8171” (trade name)manufactured by Shin-Etsu Chemical Co., Ltd. and “Chaline R-2” (tradename) manufactured by Nissin Chemical Industry Co.

A content of the denatured organopolysiloxane, for a sum of theoil-extended rubber, the olefinic resin and the post-added softeningagent taken as 100 parts by mass, is preferably 0.2 to 20 parts by mass,0.5 to 15 parts by mass, particularly preferably 1 to 10 parts by mass.The denatured organopolysiloxane functions, rather than providing aslidability, as a mutual dissolving agent for the polymer compositionand the undenatured organopolysiloxane in the polysiloxane-containingcomposition [D]. Therefore, a content of the denaturedorganopolysiloxane less than 0.2 parts by mass cannot provide asufficient mutual solubility, thus resulting in a defective dispersionof the undenatured organopolysiloxane and the polymer composition in akneader, or deteriorating a moldability such as in extrusion molding orinjection molding. On the other hand, a content exceeding 20 parts bymass tends to deteriorate the flexibility and the mechanical properties.

The polysiloxane-containing composition [D], having excellent rubberelasticity and thermoplastic property, can be easily worked with anordinary molding method for thermoplastic resin, such as injectionmolding, extrusion molding, blow molding, compression molding, vacuummolding, laminate molding or calender molding. Also a secondary workingsuch as foaming, drawing, adhesion, printing, painting or plating can beeasily executed if necessary. Therefore, the polysiloxane-containingcomposition [D] can be widely applicable not only to composite articleshaving an injection fused portion but also to ordinary worked articles.For example it is useful in automotive external and internal surfacematerials such as a bumper, an external lace, a window sealing gasket, adoor sealing gasket, a trunk sealing gasket, a roofside rail, an emblem,and internal/external surface materials, sealants or internal/externalsurface materials for aircraft and ship, sealants, internal/externalsurface materials or waterproof sheet materials for construction andbuilding, sealants for general machinery and apparatus, a packing or ahousing for consumer electric appliances, household goods, sportinggoods or the like.

[5] Crosslinking Agent

A crosslinking agent to be employed in crosslinking can be similar inany of the specific-size rubber particle-containing composition [A], theacrylate resin-containing composition [B], the maleimidecompound-containing composition [C], and the polysiloxane-containingcomposition [D]. Examples of the crosslinking agent include an organicperoxide, a phenolic resin crosslinking agent, sulfur, a sulfurcompound, p-quinone, a p-quinonedioxime derivative, a bismaleimidecompound, an epoxy compound, a silane compound, an amino resin, a polyolcrosslinking agent, a polyamine, a triazine compound and a metal soap,among which an organic peroxide and a phenolic resin crosslinking agentare preferred.

The organic peroxide preferably a 1-minute half-period temperature T_(h)(° C.) within a range of T_(m)≦T_(h)≦T_(m)+50 (° C.) in which T_(m) is amelting point (° C.) of the polyolefinic resin to be employed. A T_(h)lower than T_(m) initiates a crosslinking reaction before the rubber andthe olefinic resin are sufficiently melted and kneaded, therebydeteriorating the rubber elasticity and the mechanical strength of thethermoplastic elastomer composition. On the other hand, a T_(h)exceeding T_(m)+50 (° C.) results in a deficient crosslinking because ofan excessively low crosslinking temperature, thereby tending to reducethe rubber elasticity and the mechanical strength of the thermoplasticelastomer composition.

Examples of the organic peroxide include1,3-bis(t-butylperoxyisopropyl)benzene,2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3,2,5-dimethyl-2,5-bis(t-butylperoxy)hexene-3,2,5-dimethyl-2,5-bis(t-butylperoxy)hexane,2,2′-bis(t-butylperoxy)-p-isopropylbenzene, dicumyl peroxide, di-t-butylperoxide, t-butyl peroxide, p-menthane peroxide,1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, dilauroyl peroxide,diacetyl peroxide, t-butyl peroxybenzoate, 2,4-dichlorobenzoyl peroxide,p-chlorobenzoyl peroxide, benzoyl peroxide, di(t-butylperoxy)perbenzoate, n-butyl-4,4-bis(t-butylperoxy) valerate, andt-butylperoxyisopropyl carbonate. Among these, there is preferred acompound with a relatively high decomposition temperature such as1,3-bis(t-butylperoxyisopropyl)benzene,2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3, or2,5-dimethyl-2,5-bis(t-butylperoxy)hexane. These may be employed singlyor in a combination of two or more kinds.

Also in case of employing an organic peroxide as a crosslinking agent,an auxiliary crosslinking agent may be utilized to execute thecrosslinking reaction in a milder manner, thereby obtaining aparticularly uniform crosslinked structure. Examples of the auxiliarycrosslinking agent include a sulfur compound such as sulfur, powderedsulfur, colloidal sulfur, precipitated sulfur, insoluble sulfur,surface-treated sulfur or dipentamethylene thiuram tetrasulfide; anoxime compound such as p-quinone oxime, or p,p′-dibenzoylquinone oxime;and a polyfunctional monomer such as ethylene glycol di(meth)acrylate,diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate,tetraethylene glycol di(meth)acrylate, polyethylene glycoldi(meth)acrylate, trimethylolpropane tri(meth)acrylate, diallylphthalate, tetraallyloxy ethane, triallyl cyanurate, N,N′-m-phenylenebismaleimide, N,N′-toluylene bismaleimide, maleic anhydride,divinylbenzene, or zinc di(meth)acrylate. Among these,p,p′-dibenzoylquinone oxime, N,N′-m-phenylene bismaleimide anddivinylbenzene are particularly preferable. These may be employed singlyor in a combination of two or more kinds. Also among these auxiliarycrosslinking agent, N,N′-m-phenylene bismaleimide has a function as acrosslinking agent and can also be used as a crosslinking agent.

In case of employing an organic peroxide as the crosslinking agent, anamount of use, taking the polymer composition as 100 parts by mass, ispreferably 0.05 to 10 parts by mass, particularly 0.1 to 5 parts bymass. A content of the organic peroxide less than 0.05 parts by mass mayresult in a deficient crosslinking degree, thereby reducing the rubberelasticity and the mechanical strength of the thermoplastic elastomercomposition. On the other hand, a content exceeding 10 parts by masstends to result in an excessively high crosslinking degree, therebydeteriorating the moldability or reducing the mechanical properties.

In case of employing an organic peroxide as the crosslinking agent, anamount of the auxiliary crosslinking agent, for the polymer compositiontaken as 100 parts by mass, is preferably 10 parts by mass or less,particularly preferably 0.2 to 5 parts by mass. A content of theauxiliary crosslinking agent exceeding 10 parts by mass tends to resultin an excessively high crosslinking degree, thereby deteriorating themoldability and the mechanical properties.

Also a phenolic crosslinking agent can be a p-substituted phenolcompound represented by a following general formula (I), ano-substituted phenol-aldehyde condensate, a m-substitutedphenol-aldehyde condensate, or a brominated alkylphenol-aldehydecondensate, among which a p-substituted phenol compound is particularlypreferable.

wherein n represents an integer from 0 to 10; X represents a hydroxylgroup, a halogenated alkyl group or a halogen atom; and R represents asaturated hydrocarbon group with 1 to 15 carbon atoms.

The p-substituted phenol compound can be obtained by a condensationreaction of a p-substituted phenol and an aldehyde (preferablyformaldehyde) in the presence of an alkali catalyst.

In case of employing a phenolic crosslinking agent as the crosslinkingagent, it is preferably employed, for the polymer composition taken as100 parts by mass, in 0.2 to 10 parts by mass, particularly preferably0.5 to 5 parts by mass. A content of the phenolic crosslinking agentless than 0.2 parts by mass may result in a deficieint crosslinkingdegree, thus reducing the rubber elasticity and the mechanical strengthof the thermoplastic elastomer composition. On the other hand, a contentexceeding 10 parts by mass tends to deteriorate the moldability of thethermoplastic elastomer composition.

Such phenolic crosslinking agent may be employed singly, but acrosslinking accelerator may be employed in combination in order toregulate a crosslinking rate. Such crosslinking accelerator can be ametal halide such as stannous chloride or ferric chloride, or an organichalide such as chlorinated polypropylene, brominated butyl rubber, orchloroprene rubber.

In addition to the crosslinking accelerator, it is desirable to employ,in combination, a dispersant for example a metal oxide such as zincoxide, or stearic acid.

[6] Other Additives

In each of the specific-size rubber particle-containing composition [A],the acrylate resin-containing composition [B], the maleimidecompound-containing composition [C], and the polysiloxane-containingcomposition [D], there may be added other additives according to thenecessity, for example a lubricant; a stabilizer such as an antiagingagent, a thermal stabilizer, an antiweathering agent, a metaldeactivator, an ultraviolet absorber, a photostabilizer, or a copperpoisoning inhibitor; an auxiliary working agent, a release agent, aflame retardant, an antistatic agent, an antibacterial/antimold agent, adispersant, a platicizer, a crystal nucleating agent, a flame retardant,a stickiness provider, an auxiliary foaming agent, a colorant such astitanium oxide or carbon black, a metal powder such as ferrite,inorganic fibers such as glass fibers or metal fibers, organic fiberssuch as carbon fibers or aramide fibers, composite fibers, inorganicwhiskers such as potassium titanate whiskers, a filler such as glassbeads, glass balloons, glass flakes, asbestos, carbon black, mica,calcium carbonate, magnesium carbonate, clay, caolin, talc, wet-processsilica, dry-process silica, talc, calcium silicate, hydrotalcite,caolin, diatomaceous earth, graphite, pumice, ebonite powder, cottonflock, cork powder, barium sulfate, fluorinated resin, polymer beads,natural silicate, or synthetic silicate or a mixture thereof, a fillersuch as polyolefin wax, cellulose powder, fluorine powder, siliconepowder, rubber powder or wood powder, silicone oil or a low-molecularpolymer.

[7] Method for Producing Thermoplastic Elastomer Composition

The specific-sized rubber particle-containing composition [A], theacrylate resin-containing composition [B], the maleimidecompound-containing composition [C], and the polysiloxane-containingcomposition [D] (these compositions [A] to [D] may hereinafter becollectively called “thermoplastic elastomer composition”) can beproduced by similar methods.

(1) A Producing Method Utilizing a Batch-type Closed Kneader and aContinuous Extruder

The thermoplastic elastomer composition can be produced by mixing andkneading a polymer composition including a rubber and a polyolefinicresin, at least a part of a crosslinking agent and other additives ifnecessary, in a batch-type closed kneader to obtain a dispersed blend,and then dynamically crosslinking such blend in a continuous extrudersuch as a two-shaft extruder. It can also be produced by mixing anddispersing a polymer composition including a rubber and a polyolefinicresin, and other additives excluding a crosslinking agent if necessaryin a batch-type closed kneader to obtain a blend, and then dynamicallycrosslinking a composition including such blend, a crosslinking agentand other components if necessary in a continuous extruder such as atwo-shaft continuous extruder. Such “dynamic crosslinking” means acrosslinking under both a shearing force and a heating. Also the mixingstep for mixing and dispersion, and the crosslinking step for dynamiccrosslinking may be executed in continuation.

1) Batch-type Closed Kneader

The aforementioned closed kneader can be, for example, a pressurizedkneader, a Banbury mixer or a Brabender mixer.

In case of mixing and dispersing the polymer composition with a closedkneader, a method of supplying the softening agent is not particularlylimited, and the softening agent may be blended in advance in thepolymer composition or may be supplied, separately from the polymercomposition, to closed kneader. It is also possible to supply thesoftening agent after the mixing and dispersion of the polymercomposition, or to utilize an oil-extended rubber.

Also, particularly in the preparation of the polysiloxane-containingcomposition [D], in case of melt kneading the polymer compositionwithout the crosslinking agent in the closed kneader, the undenaturedand denatured organopolysiloxanes and the softening agent may be mixedin advance with the polymer composition, or respectively supplied to theclosed kneader without mixing in advance, and a procedure is notparticularly restricted. Also the undenatured organopolysiloxane, thedenatured organopolysiloxane and the softening agent may be added afterthe melt kneading of the polymer composition or may be charged in theclosed kneader from the beginning together with the polymer compositionfor melt kneading, and such procedure is not particularly restricted.

Also, for charging the blend prepared in the closed kneader into thecontinuous extruder, the blender is preferably cut in advance into smallpieces. The small pieces may be prepared by pellet formation with afeeder-ruder or by forming a sheet with a roll mill and forming pelletswith a sheet pelletizer, and a method for cutting the blend is notparticularly limited.

2) Continuous Extruder

The continuous extruder is not particularly limited, and can be aone-shaft extruder, a two-shaft extruder or a two-shaft rotary extruder,however there is preferred a two-shaft extruder, particularly preferablywith an L/D ratio (ratio of effective screw length L and externaldiameter D) equal to or larger than 30, further preferably 36 to 60.Such two-shaft extruder can be of any type, for example with mutuallymeshing two screws or with two screws without meshing. There is morepreferred an extruder in which two screws have a same rotating directionand are mutually meshing. Examples of such two-shaft extruder include GTmanufactured by Ikegai Ltd., KTX manufactured by Kobe Steel Ltd., TEXmanufactured by Japan Steel Work Co., TEM manufactured by ToshibaMachinery Co. and ZSK manufactured by Warner Inc. (foregoing all tradenames).

In case of producing the thermoplastic elastomer composition by dynamiccrosslinking with a continuous extruder, the crosslinking agent may besupplied for example by a method of mixing it by a blend mixer inadvance with a blend to be subjected to the crosslinking reaction andthen supplying the mixture to the continuous extruder, or a method ofsupplying from a barrel aperture provided between a feed hopper and adie, and such supplying method is not particularly restricted.

Also a method of adding the filler or the like. is not particularlylimited, and they may be added in the closed kneader, or in thecontinuous extruder, or in both.

A condition of the dynamic crosslinking process is variable depending onthe melting point of the employed olefinic resin and the kind of thecrosslinking agent, however a process temperature is preferably within arange from a melting point (T_(m)) of the olefinic resin to 250° C. Atemperature lower than the melting point of the olefinic resin is unableto sufficiently melt and knead the rubber and the olefinic resin,thereby resulting in an insufficient kneading to eventually deterioratethe mechanical properties of the thermoplastic elastomer composition. Onthe other hand, a temperature exceeding 250° C. tends to cause adeterioration in the rubber, thereby reducing the mechanical propertiesof the thermoplastic elastomer composition.

(2) A Producing Method Utilizing a Continuous Two-Shaft Kneader WithDifferent Rotating Directions and a Two-Shaft Extruder With a SameRotating Direction

The thermoplastic elastomer composition can also be produced bysupplying a polymer composition including a rubber and an olefinic resinto an extrusion apparatus constituted of a serial connection of anupstream continuous two-shaft kneader with different rotating directionsand a downstream two-shaft extruder with a same rotating direction, froma raw material introducing part of the continuous two-shaft kneader withdifferent rotating directions thereby mixing and dispersing the rawmaterial composition in the continuous two-shaft kneader with differentrotating directions, and supplying the kneaded substance, with atemperature of the kneaded substance maintained at 250° C. or less at anexit of the continuous two-shaft kneader with different rotatingdirections, to the two-shaft extruder with a same rotating directionthereby executing a dynamic crosslinking.

In this producing method, the continuous two-shaft kneader withdifferent rotating directions executes a melt kneading of the suppliedpolymer composition and a mixing and a dispersion of the crosslinkingagent, and a kneaded substance controlled at a predetermined temperatureor lower is supplied to the two-shaft extruder with a same rotatingdirection to complete a dynamic crosslinking reaction. A temperature ofthe kneaded substance at the exit of the continuous two-shaft kneaderwith different rotating directions is variable depending on the kind ofthe employed olefinic resin and the crosslinking agent, however it hasto be controlled at a temperature capable of executing the melt kneadingof the polymer composition in the continuous two-shaft kneader withdifferent rotating directions in a state of suppressing the proceedingof the crosslinking reaction, and is maintained at 250° C. or lower inorder to prevent deterioration of the rubber and the olefinic resincontained in the polymer composition.

Also the thermoplastic elastomer composition can be produced bysupplying a polymer composition including a rubber, an olefinic resinand an organic peroxide having a 1-minute half-period temperature T_(h)(° C.) within a range of T_(m)≦T_(h)≦T_(m)+50 (° C.) in which T_(m) is amelting point (° C.) of the olefinic resin, to an extrusion apparatusconstituted of a serial connection of an upstream continuous two-shaftkneader with different rotating directions and a downstream two-shaftextruder with a same rotating direction, from a raw material introducingpart of the continuous two-shaft kneader with different rotatingdirections thereby mixing and dispersing the polymer composition in thecontinuous two-shaft kneader with different rotating directions, and,with a temperature (t_(a)) of the kneaded substance maintained within arange of T_(h)−30≦t_(a)≦T_(h)+30 (° C.) at an exit of the continuoustwo-shaft kneader with different rotating directions and executing adynamic crosslinking in the two-shaft extruder with a same rotatingdirection.

In this producing method, the continuous two-shaft kneader withdifferent rotating directions executes a melt kneading of the suppliedpolymer composition and a mixing and a dispersion of the crosslinkingagent, and a kneaded substance controlled at a predetermined temperatureor lower is supplied to the two-shaft extruder with a same rotatingdirection to complete a dynamic crosslinking reaction. A temperaturet_(a) of the kneaded substance at the exit of the continuous two-shaftkneader with different rotating directions is variable depending on thekind of the employed olefinic resin and the crosslinking agent, howeverit has to be controlled at a temperature capable of executing the meltkneading of the polymer composition in the continuous two-shaft kneaderwith different rotating directions in a state of suppressing theproceeding of the crosslinking reaction. Therefore, the temperature hasto be equal to or lower than a temperature capable of suppressing theproceeding of the crosslinking reaction. In case of employing at leastan organic peroxide as the crosslinking agent, for a 1-minutehalf-period temperature T_(h), there is required a range ofT_(h)−30≦t_(a)≦T_(h)+30(° C.) [preferably T_(h)−20≦t_(a)≦T_(h)+25 (° C.)and more preferably T_(h)−10≦t_(a)≦T_(h)+20(° C.)]. In case the kneadedsubstance at the exit of the continuous two-shaft kneader with differentrotating directions has a temperature t_(a) exceeding T_(h)+30 (° C.),the kneaded substance is supplied, in a state wherein a crosslinkingreaction has proceeded rapidly or has been completed in the continuoustwo-shaft kneader with different rotating directions, to the two-shaftextruder with a same rotating direction, whereby the thermoplasticelastomer composition is deteriorated in the mechanical properties andthe moldability. On the other hand, a temperature t_(a) less thanT_(h)−30 (° C.) results in an insufficient melt kneading, thusdeteriorating the mechanical strength of the thermoplastic elastomercomposition.

Examples of the continuous two-shaft kneader with different rotatingdirections include CIM manufactured by Japan Steel Work Co., MixtronFCM/NCM/LCM/ACM manufactured by Kobe Steel Ltd. (foregoing being alltrade names).

The two-shaft extruder with a same rotating direction is notparticularly restricted, but preferably is a two-shaft extruderpreferably with an L/D ratio (ratio of effective screw length L andexternal diameter D) equal to or larger than 30, more preferably 36 to60.

The crosslinking agent is not particularly limited in a supplyingmethod, and can be supplied in a mixed with the polymer compositionand/or in a mixing and dispersing step, and more specifically, there canbe adopted 1) a method of mixing it by a blend mixer in advance with thepolymer composition to be subjected to the crosslinking reaction andthen supplying the mixture to the continuous two-shaft kneader withdifferent rotating directions, or 2) a method of supplying from a feedhopper of the continuous two-shaft kneader with different rotatingdirections. Also there may be employed 3) a method of supplying from abarrel aperture provided between a feed hopper of the continuoustwo-shaft kneader with different rotating directions and the exit of thekneader.

In case of producing the thermoplastic elastomer composition in aconnected apparatus, a supplying method for the softening agent, thefiller or the like. is also not particularly restricted, and there maybe employed 1) a method of mixing in advance by a blend mixer with therubber and the olefinic resin to be subjected to the crosslinkingreaction and then supplying the mixture to the continuous two-shaftkneader with different rotating directions, 2) a method of supplyingfrom a feed hopper of the continuous two-shaft kneader with differentrotating directions, the two-shaft extruder with a same rotatingdirection or both, 3) a method of supplying from a barrel apertureprovided between a feed hopper and a die of the continuous two-shaftkneader with different rotating directions, the two-shaft extruder witha same rotating direction or both, or 4) a method of supplying to thetwo-shaft extruder with a same rotating direction utilizing a sidefeeder.

Also, in the preparation of the polysiloxane-containing composition [D],in case of producing the thermoplastic elastomer composition with acontinuous extruder, the undenatured and denatured organopolysiloxanesmay be supplied, in case of powder, by a method of mixing in advance bya mixer with the polymer composition to be subjected to the crosslinkingreaction and then supplying the mixture to the continuous extruder, and,in case of liquid, by a method of mixing in advance by a mixer with thepolymer composition to be subjected to the crosslinking reaction andthen supplying the mixture to the continuous extruder, or by a method ofsupplying from a barrel aperture provided between a feed hopper and adie.

Also a pelletizing of the thermoplastic elastomer composition producedby these methods can be realized by a known pelletizing apparatus suchas a strand cut, an underwater cut, a mist cut or a hot cut and is notparticularly limited.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, the present invention will be explained in moredetails by examples, however the present invention is not restricted bysuch examples unless the scope of the invention is exceeded.

1. Example on the Specific-Size Rubber Particle-containing Composition[A]

Rubber, crystalline olefinic resin, amorphous olefinic resin, softeningagent, crosslinking agent or the like. employed as raw materials were asfollows.

[1] Raw Materials

(1) Rubber

1) EPDM (a11): ethylene/propylene/5-ethylidene-2-norbornene ternarycopolymer rubber, ethylene content: 66 mass %, 5-ethylidene-2-norbornenecontent: 4.5 mass %, a limiting viscosity measured at 135° C. indecaline: 4.7 dl/g, a mineral oil type softening agent (trade name DianaProcess Oil PW-380, manufactured by Idemitsu Kosan Co. Ltd.,) content:50 mass %;

2) EPDM (a12): ethylene/propylene/5-ethylidene-2-norbornene ternarycopolymer rubber, ethylene content: 66 mass %, 5-ethylidene-2-norbornenecontent: 4.5 mass %, a limiting viscosity measured at 135° C. indecaline: 3.8 dl/g, a mineral oil type softening agent (trade name DianaProcess Oil PW-380, manufactured by Idemitsu Kosan Co., Ltd.) content:40 mass %;

3) EPDM (a13): ethylene/propylene/5-ethylidene-2-norbornene ternarycopolymer rubber, ethylene content: 66 mass %, 5-ethylidene-2-norbornenecontent: 4.5 mass %, a limiting viscosity measured at 135° C. indecaline: 2.8 dl/g, a mineral oil type softening agent (trade name DianaProcess Oil PW-380, manufactured by Idemitsu Kosan Co., Ltd.) content:20 mass %.

(2) Olefinic Resin

1) Crystalline olefinic resin (b11): a propylene polymer, density: 0.90g/cm³, MFR (temperature 230° C., load 2.16 kgs): 5 g/10 minutes, (tradename Novatec PP MA4, manufactured by Nippon Polychem Co.);

2) Crystalline olefinic resin (b12): a propylene/ethylene randomcopolymer, density: 0.90 g/cm³, MFR (temperature 230° C., load 2.16kgs): 3 g/10 minutes, (trade name Novatec PP BC5CW, manufactured byNippon Polychem Co.);

3) Crystalline olefinic resin (b13): a propylene/ethylene randomcopolymer, density: 0.90 g/cm³, MFR (temperature 230° C., load 2.16kgs): 23 g/10 minutes, (trade name Novatec PP FL25R, manufactured byNippon Polychem Co.);

4) Amorphous olefinic resin (b2): a propylene/1-butene amorphouscopolymer; propylene content: 71 mol %, melt viscosity: 8 Pa·s, density:0.87 g/cm³, Mn: 6500, (trade name APAO UT2780, manufactured by UbeIndustries Ltd.);

(3) Mineral oil type softening agent (g1): hydrogenated paraffin oil(trade name Diana Process Oil PW 380, manufactured by Idemitsu KosanCo., Ltd);

(4) Crosslinking Agent

1) Crosslinking agent (h1): 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane-3,1-minute half-period temperature: 194.3° C. (trade name Perhexa 25B-40,manufactured by NOF Corp.);

2) Crosslinking agent (h2): 2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3,1-minute half-period temperature: 179.8° C. (trade name Perhexine25B-40, manufactured by NOF Corp.);

3) Crosslinking agent (h3): divinylbenzene (purity 55%), (manufacturedby Sankyo Kasei Co.);

(5) Antiaging agent (j1): trade name Irganox 1010 (manufactured by CibaSpecialty Chemicals Co.);

(6) Lubricant [silicone oil (k1)]: organopolydimethylsiloxane (tradename SH-200(100 cSt), manufactured by Toray Dow Corning Silicone Ltd.).

[2] Production of Specific-Sized Rubber Particle-containing Composition[A]

(1) Producing Method With a Closed Kneader+a Continuous Extruder(Producing Method 1)

EXAMPLES 1, 3 AND 5

A raw material composition of a formulation shown in Table 1 excluding acrosslinking agent was charged in a pressurized kneader (manufactured byMoriyama Company Ltd.) heated to 150° C., and was kneaded for 15 minutesat 40 rpm until the components were uniformly dispersed. Then thecomposition in a melting state was pelletized with a feeder-ruder(manufactured by Moriyama Company Ltd.) set at 180° C. and 40 rpm. Theobtained pellets were added with crosslinking agents (h1)-(h3) of aformulation shown in Table 1 and were mixed for 30 seconds in a Henshelmixer. Then the mixture was supplied by a weight type feeder (trade nameKF-C88, manufactured by Kubota Co.) with a discharge amount of 40 kg/hrto a two-shaft extruder (non-meshing screws in a same direction, L/D(external diameter 45 mm, ratio of effective screw length L and externaldiameter D)=38.5, trade name PCM-45, manufactured by Ikegai Ltd.) andwas extruded under dynamically heat-treating with a cylinder temperaturesetting at 200° C. and a screw revolution of 300 rpm to produce aspecific-sized rubber particle-containing composition [A].

(2) Producing Method With a Two Connected Apparatuses of a ContinuousTwo-Shaft Kneader With Different Rotating Directions+a Two-ShaftExtruder With a Same Rotating Direction (Producing Method 2)

EXAMPLES 2, 4 AND 6 AND COMPARATIVE EXAMPLE 4

A raw material composition of a formulation shown in Table 1 was mixedfor 30 seconds in a Henshel mixer. Then the mixed raw materialcomposition was supplied with two weight type feeders (trade nameKF-C88, manufactured by Kubota Co.) with a discharge amount of 40 kg/hrto an apparatus formed by connecting an upstream continuous two-shaftkneader with different rotating directions (two meshing rotors indifferent directions, L/D=10, trade name Mixtron LCM, manufactured byKobe Steel Ltd.) and a downstream two-shaft extruder with a samerotating direction (non-meshing screws in a same direction, L/D=42,trade name TEX 44SS, manufactured by Japan Steel Work Co.) from a rawmaterial inlet of the continuous two-shaft kneader with differentrotating directions, and was melted and kneaded under a cylindertemperature setting of 80° C., a rotor revolution of 350 to 800 rpm, agate aperture of 1 to 40% and an orifice aperture of 100%. Then thecomposition in the melting state was supplied to the two-shaft extruderwith a same rotating direction directly connected to the continuoustwo-shaft kneader with different rotating directions and was subjectedto a crosslinking reaction by dynamically heat-treating with a cylindertemperature setting of 200° C. and a screw revolution of 400 rpm toobtain a specific-sized rubber particle-containing composition [A]. Themineral oil type softening agent was pressed in from a cylinder of afirst kneading rotor of the continuous two-shaft kneader with differentrotating directions.

(3) Producing Method Utilizing a Continuous Extruder (Producing Method3)

COMPARATIVE EXAMPLES 1 TO 3

A raw material composition of a formulation shown in Table 1 was mixedfor 30 seconds in a Henshel mixer. Then a rubber and an olefinic resin,added with various additives, were supplied with two weight type feeders(trade name KF-C88, manufactured by Kubota Co.) with a discharge amountof 40 kg/hr to a two-shaft extruder (non-meshing screws in a samedirection, L/D=38.5, trade name PCM-45, manufactured by Ikegai Ltd.) andwere extruded under dynamically heat-treating with a cylindertemperature setting of 200° C. and a screw revolution of 300 rpm, toobtain a specific-sized rubber particle-containing composition [A].

In the productions with these three producing methods, a temperature ofthe blend at the exit of the continuous two-shaft kneader with differentrotating directions and a temperature of the blend at the exit of thetwo-shaft extruder with a same rotating direction were measured by anon-contact thermometer (trade name: PT-3LF, manufactured by Optex Co.).

[3] Evaluation of the Specific-Sized Rubber Particle-containingComposition [A]

Following items were measured in order to evaluate the obtainedspecific-sized rubber particle-containing compositions [A]:

-   (1) melt flow rate (MFR): measured at 230° C. and a load of 10 kg;-   (2) hardness: measured according to JIS K 6253;-   (3) tensile strength at break and tensile elongation at break:    measured according to JIS K 6251;-   (4) permanent compression set: measured according to JIS K 6262;-   (5) extrusion workability: A labplast mill extruder (external    diameter=20 mm, L/D=25, manufactured by Toyo Seiki Co.) was used to    extrude a flat slab (lip width: 25 mm, thickness: 1.5 mm) under    following conditions and an appearance was visually evaluated. An    article with a smooth surface and an edge was evaluated as “◯”, and    any other article was evaluated as “X”.    -   (setting of labplast mill extruder)    -   cylinder C1: 180° C.    -   cylinder C2: 190° C.    -   cylinder C3: 210° C.    -   die: 205° C.    -   screw revolution: 40 rpm.        (6) Particles

As an index of melt kneading, “particles” of the specific-sized rubberparticle-containing composition [A] were measured. The “particles” meanvisible giant gel particles, an unmelted olefinic rein, or fish-eyes,generated in the production of the specific-sized rubberparticle-containing composition [A], by a lack of sufficient meltkneading of the rubber and the olefinic resin in the dynamicallytreating in the presence of the crosslinking agent. The “particles” wereevaluated by forming the specific-sized rubber particle-containingcomposition [A] into a thin sheet by electrically heated type 6 inchrolls (manufactured by Kansai Roll Co.) under a setting of a temperatureof 180° C. and a gap of rolls of 0.5 mm, and a number of the “particles”present in a sheet of 20×20 cm was visually counted. Criteria ofevaluation were as follows:

-   -   0 to less than 30: very few    -   30 to less than 100: few    -   100 or more: many        (7) Gel Fraction: Measured by the Aforementioned Method.        (8) TEM Photograph

A TEM photograph of the specific-sized rubber particle-containingcomposition [A] was obtained by forming a thin slice of a specific-sizedrubber particle-containing composition [A] with a frozen microtome,dyeing it with ruthenium tetroxide, and photographing the dyed slicewith a magnification of 2000 times under a transmission electronmicroscope (trade name H-7500, manufactured by Hitachi Ltd.).

In the image analysis of the TEM photograph, an image analysis softwareImage-Pro Plus Ver. 4.0 for Windows (manufactured by Media CyberneticsInc.) was used to obtain areas of crosslinked rubber particles.

Based on the areas of the determined crosslinked rubber particles, theaforementioned equations were used to determine a number-averagedparticle diameter dn and a volume-averaged particle diameter dv, anddv/dn was calculated from these values.

TABLE 1 Oil- Limiting Mineral oil extended viscosity softening agentExample Comparative Example rubber (dl/g) content (mass %) 1 2 3 4 5 6 12 3 4 oil-extended 4.7 50 — — — — 75(37.5) 75(37.5) — — 75(37.5) — EPDM(a11) oil-extended 3.8 40 80(48) 80(48) — — — — 80(48) — — 80(48) EPDM(a12) oil-extended 2.8 20 — — 75(60) 75(60) — — — 75(60) — — EPDM (a13)crystalline olefinic resin (b11) — — 25 25 — — — 25 — — crystallineolefinic resin (b12) 20 20 — — — — 20 — — 20 crystalline olefinic resin(b13) — — — — 7 7 — — 7 — amorphous olefinic resin (b2) — — — — 7 7 — —7 — post-addition mineral oil type — — — — 11 11 — — 11 — softeningagent (g1) softening agent content (mass 66.7 66.7 25 25 129 129 66.7 25129 66.7 parts) with rubber as 100 parts content (mass part) EPDM 70.670.6 70.6 70.6 72.8 72.8 70.6 70.6 70.6 70.6 with sum of rubber totalolefinic 29.4 29.4 29.4 29.4 27.2 27.2 29.4 29.4 27.2 29.4 and olefinicresins resins as 100 parts crosslinking agent (h1) 1 1 — — — — — — — 1crosslinking agent (h2) — — 0.7 0.7 1 1 — 0.7 1 — crosslinking agent(h3) 1.2 1.2 0.7 0.7 1.2 1.2 1.2 0.7 1.2 1.2 total crosslinking agents(mass part) 3.2 3.2 1.6 1.6 4.3 4.3 1.8 1.6 4.3 3.2 with sum of rubberand olefinic resin as 100 mass parts antiaging agent (j1) 0.1 0.1 0.10.1 0.1 0.1 0.1 0.1 0.1 0.1 silicone oil (k1) 0.2 0.2 0.2 0.2 0.2 0.20.2 0.2 0.2 0.2 producing method 1 2 1 2 1 2 3 3 3 2 gate aperture (%)of continuous two-shaft — 40 — 15 — 1 — — — 10 kneader with differencerotating directions orifice aperture (%) of continuous two-shaft — 100 —100 — 100 — — — 30 kneader with difference rotating directions rotorrevolution (rpm) of continuous — 750 — 350 — 800 — — — 500 two-shaftkneader with difference rotating directions blend temperature (° C.) atexit of — 194 — 196 — 169 — — — 261 continuous two-shaft kneader withdifference rotating directions blend temperature (° C.) at exit 225 222266 275 251 247 246 273 244 251 of two-shaft extruder with a samerotating directions <physical MFR (g/10 min) 25 10 17 10 75 120 46 25143 5 properties> hardness (type A durometer) 73 75 86 87 49 50 73 87 4975 tensile strength at 8.1 9.9 9.8 9.9 3.9 4.3 7 9.2 3.2 5.4 break (MPa)tensile elongation at 600 640 650 670 620 650 590 630 600 530 break (%)permanent compression 38 34 45 49 38 33 45 56 40 39 set (%) extrusionworkability ◯ ◯ ◯ ◯ ◯ ◯ X X X X particle few very few very few few fewmany many many many few gel fraction (%) 97.4 98.7 97.8 98.9 99.4 99.397.9 98.5 99.1 98.1 Image analysis number-averaged 0.773 0.567 0.6720.598 0.729 0.644 1.304 1.228 1.173 2.134 of TEM particle sizephotograph dn (μm) volume-averaged 1.016 0.722 0.885 0.718 0.938 0.7592.127 1.998 1.862 3.677 particle size dv (μm) dv/dn 1.314 1.273 1.3171.201 1.287 1.179 1.631 1.627 1.587 1.723 Parenthesized number inoil-extended EPDM column indicates EPDM content (parts by mass).[4] Result of Example

Based on Table 1, the specific-sized rubber particle-containingcompositions [A] (Examples 1, 3 and 5) obtained by the producing method1 were excellent in the physical properties and the extrudingworkability, and molded articles showed few particles. Among thespecific-sized rubber particle-containing compositions [A] produced bythe producing method 2, the Comparative Example 4 had a blendtemperature t_(a) higher than 250° C. at the exit of the continuoustwo-shaft kneader with different rotating directions, and was inferiorin the extrusion workability. Also a molded article showed manyparticles, a large average particle size of the crosslinked rubberparticles and a high dv/dn ratio. On the other hand, the Examples 2, 4and 6 had a blend temperature t_(a) lower than 250° C. at the exit ofthe continuous two-shaft kneader with different rotating directions, andsatisfied a relation of T_(h)−30≦t_(a)≦T_(h)+30 (° C.) with the 1-minutehalf-period temperature T_(h) of the crosslinking agent. Also they wereexcellent in the extrusion workability and showed few particles in themolded articles, particularly very few in the Examples 2 and 4. Also thenumber-averaged particle size dn was 0.55 to 0.65 μm, with the dv/dnratio of 1.18 to 1.27, satisfactory in any example.

While the specific-sized rubber particle-containing compositions [A]produced by the producing method 3 (Comparative Examples 1 to 3) wereinferior in the extrusion workability and showed many particles, a largeaveraged particle size of the crosslinked rubber particles and a highdv/dn ratio.

2. Example on the Acrylate Resin-containing Composition [B]

Rubber, crystalline olefinic resin, amorphous olefinic resin, softeningagent, crosslinking agent or the like. employed as raw materials werefollows.

[1] Raw Materials

(1) ethylene•α-olefin random copolymer rubber (a11):ethylene/propylene/5-ethylidene-2-norbornene ternary copolymer rubber,ethylene content: 66 mass %, 5-ethylidene-2-norbornene content: 4.5 mass%, a limiting viscosity [η] measured at 135° C. in decaline: 4.7 dl/g, amineral oil type softening agent (trade name Diana Process Oil PW-380,manufactured by Idemitsu Kosan Co., Ltd.) content: 50 mass %;

(2) Olefinic Resin

1) Crystalline olefinic resin (b13): a propylene/ethylene randomcopolymer, density: 0.90 g/cm³, MFR (temperature 230° C., load 2.16kgs): 23 g/10 minutes, (trade name Novatec PP FL25R, manufactured byNippon Polychem Co.);

2) Amorphous olefinic resin (b2): a propylene/1-butene amorphouscopolymer; propylene content: 71 mol %, melt viscosity: 8 Pa·s, density:0.87 g/cm³, Mn: 6500, (trade name APAO UT2780, manufactured by UbeIndustries Ltd.);

(3) (Meth)acrylate resin (c1): a methyl methacrylate/methyl acrylatecopolymer; density: 1.19 g/cm³, MFR (temperature 230° C., load 3.8 kgs):8 g/10 minutes, (trade name Parapet G, manufactured by Kuraray Ltd.);

(4) Hydrogenated Diene Polymer (d1)

A hydrogenated diene polymer was synthesized by a following method. Alsomeasurements were made by following methods:

1) vinyl aromatic compound content: measured by an infrared analysisbased on a phenyl group absorption at 679 cm⁻¹;

2) vinyl bond content of conjugate diene: calculated by Morello methodbased on infrared analysis;

3) hydrogenation rate: calculated from ¹H-NMR spectrum at 90 MHzemploying carbon tetrachloride as a solvent;

4) weight average molecular weight: calculated by polystyreneconversion, utilizing gel permeation chromatography (GPC) at 38° C.,utilizing tetrahydrofuran as a solvent.

Method of Synthesis of Hydrogenated Diene Polymer

In an autoclave with an internal volume of 5 liters, 2.5 kgs ofcyclohexane, 15 g of tetrahydrofuran, 110 g of styrene (block Acomponent), and 0.55 g of n-butyl lithium were charged and polymerizedat 50° C. to a conversion yield of 98% or higher. Then 220 g of1,3-butadiene (block B component) were added and polymerized to aconversion yield of 98% or higher, and 110 g of styrene (block Acomponent) were further added and polymerized to a conversion yield of100%.

After the completion of the polymerization, the reaction liquid wasmaintained at 70° C., 0.33 g of n-butyl lithium, 0.61 g oft-hydroxy-4-methyl-2-pentanone, 0.21 g of bis (cyclopentadienyl)titanium dichloride and 0.76 g of diethyl aluminum chloride were addedand reacted for 1 hour at a hydrogen pressure of 10 kg/cm² to achievehydrogenation. The reaction liquid was charged and mixed in a largeamount of methyl alcohol, and a precipitated solid was recovered anddried to obtain a block copolymer. This hydrogenated diene polymer (d1)was of A-B-A type, and had a hydrogenation rate of 95%, a 1,2-vinyl bondcontent in the butadiene unit of the block B of 80%, a mass ratio ofblock A/block B of 50/50 and a weight average molecular weight of100,000.

(5) Crosslinking Agent and Auxiliary Crosslinking Agent

1) Crosslinking agent (h1): 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane(trade name Perhexa 25B-40, manufactured by NOF Corp.);

2) Auxiliary crosslinking agent (i1): divinylbenzene (purity 55%),(manufactured by Sankyo Kasei Co.);

3) Auxiliary crosslinking agent (i2): trade name Vulnoc PM (manufacturedby Ouchishinko Chemical Industries Co., Ltd.)

(6) Other Additives

1) Antiaging agent (j1): trade name Irganox 1010 (manufactured by CibaSpecialty Chemicals Co.);

2) Silicone oil (k1): organopolydimethylsiloxane, trade name SH-200 (100cSt), manufactured by Toray Dow-Corning Silicone Co.

EXAMPLE 7

[2] Production of Acrylate Resin-containing Composition [B]

80 parts by mass of ethylene•α-olefin random copolymer rubber (a11), 10parts by mass of crystalline olefinic resin (b13), 5 parts by mass ofamorphous olefinic resin (b2), 5 parts by mass of (meth)acrylate resin(c1), 2 parts by mass of hydrogenated diene polymer (d1), 0.1 parts bymass of antiaging agent (i2), and 0.2 parts by mass of silicone oil (k1)were charged in a dual-arm type pressurized kneader of a volume of 10liters (manufactured by Moriyama Company Ltd.) heated at 150° C. andkneaded for 20 minutes at 40 rpm. Then the composition in a meltingstate was pelletized with a feeder-ruder (manufactured by MoriyamaCompany Ltd.) set at 180° C. and 40 rpm. The obtained pellets were addedwith 0.5 parts by mass of a crosslinking agent (h2) and 0.5 parts bymass of an auxiliary crosslinking agent (i2) and were mixed for 30seconds in a Henshel mixer. Then a two-shaft extruder (trade namePCM-45, manufactured by Ikegai Ltd., with completely meshing screws in asame direction, L/D (ratio of a screw flight length L and screw diameterD)=33.5) was used to execute an extrusion by dynamically heat-treatingunder conditions of 230° C., 300 rpm and a retention time of 2 minutes,thereby producing an acrylate resin-containing composition [B], whichwas a pellet-shaped dynamically crosslinked thermoplastic elastomercomposition.

[3] Preparation of Test Piece

The pellets of the obtained thermoplastic elastomer were injectionmolded with an injection molding machine (trade name N-100, manufacturedby Japan Steel Work Co.) to obtain a sheet of a thickness of 2 mm, alength of 120 mm and a width of 120 mm, which was used for variousevaluations.

[4] Evaluation of the Acrylate Resin-containing Composition [B]

-   (1) fluidity: a melt flow rate was measured at 230° C. and under a    load of 10 kg as an index of fluidity;-   (2) hardness: measured according to JIS K 6253 as an index of    flexibility;-   (3) tensile strength at break and tensile elongation at break:    measured according to JIS K 6251;-   (4) permanent compression set: measured according to JIS K 6262 as    an index of rubber elasticity and under conditions of 70° C. and 22    hours;-   (5) scratch resistance test 1): A taber scratch tester manufactured    by Toyo Seiki Mfg., Co. was used to scan a surface of a molded sheet    with a metal craw (of tungsten carbide) under a predetermined load    (initially 10 g and stepwise increased by 10 g), and a load causing    a scratch was measured. A larger load indicates a better scratch    resistance.-   (6) scratch resistance test 2): A surface of a molded sheet was    scratched with a nail of a thumb, and a level of scratch was    visually evaluated.

Criteria of evaluation were ◯: no scratch, Δ: slight scratch, X: deepscratch.

The results of these evaluations are shown in Table 2.

EXAMPLES 8-10 AND COMPARATIVE EXAMPLES 5-10

The pellet-shaped acrylate resin-containing composition [B] and testpieces were prepared in the same manner as in Example 7, withformulations as shown in Table 2. The result of evaluations of theacrylate resin-containing composition [B] are shown in Table 2.

TABLE 2 Example Comparative Example 7 8 9 10 5 6 7 8 9 10 oil-extendedEPDM (all) (mineral oil 80(40) 65(32.5) 70(35) 60(30) 70(35) 85(42.5)80(40) 65(32.5) 70(35) 60(30) softening agent content 50 mass %)crystalline olefinic (b13) 10 20 10 22 25 13 20 22 22 22 resin amorphousolefinic (b2) 5 — 5 3 5 2 — 3 3 3 resin (meth)acrylate (c1) 5 10 10 10 —— — 10 — 10 resin hydrogenated diene (d1) 2 5 5 5 — — — — 5 5 polymercontent (mass %) EPDM 64.5 48.1 53.8 42.9 53.8 73.9 66.7 48.1 53.8 42.9with sum of rubber, total olefinic resin 24.2 29.6 23.1 35.7 46.2 26.133.3 37 38.5 35.7 olefinic resin, (meth)acrylate 8.1 14.8 15.4 14.3 — —— 14.9 — 14.3 (meth)acrylate resin resin and hydrogenated 3.2 7.5 7.77.1 — — — — 7.7 7.1 hydrogenated diene diene polymer polymer taken as100 mass % crosslinking agent (h1) 0.5 1 1 1 1 1 1 1 1 — auxiliary (i1)— 1.25 1.25 — 0 1.25 1.25 — — — crosslinking agent (i2) 0.5 — — 0.5 0.5— — 0.5 0.5 — antiaging agent (j1) 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.10.1 silicone oil (k1) 0.2 0.2 0.2 0.2 1.2 0.2 0.2 0.2 0.2 0.2 fluidityMFR(190° C. × 21.1 N) 3 10 4 32 35 2 6 30 39 14 [g/10 min] mechanicalhardness (type A 60 80 68 88 86 60 74 86 82 86 properties durometer)tensile strength at break 6.2 7 5.4 8.5 10.3 7 8.2 5.1 9.8 4.1 [MPa]tensile elongation at 740 650 720 650 760 600 650 660 680 720 break (%)permanent CS(701° C. × 22 hr)[%] 45 51 50 61 51 58 40 65 61 90compression set scratch resistance {circle around (1)} 40 50 40 50 10 orless 10 or less 10 or 40 10 or 10 or less less less {circle around (2)}◯ ◯ ◯ ◯ X X X ◯ X X Parenthesized number in oil-extended EPDM columnindicates EPDM content (parts by mass).(6) Result of Example

Table 2 indicates that Examples 7 to 10 are excellent in the scratchresistance, the mechanical properties and the rubber elasticity. WhileComparative Examples 5 to 7 are inferior in the scratch resistancebecause of absence of (meth)acrylate resin and hydrogenated dienepolymer. Also Comparative Example 8 is inferior in the mechanicalproperties because of absence of hydrogenated diene polymer. AlsoComparative Example 9 is inferior in the scratch resistance because ofabsence of (meth)acrylate resin, and Comparative Example 10 is inferiorin the mechanical properties, the rubber elasticity and the scratchresistance because of absence of crosslinking.

3. Maleimide Compound-containing Composition [C]

Rubber, crystalline olefinic resin, amorphous olefinic resin, softeningagent, crosslinking agent or the like. employed as raw materials were asfollows.

[1] Raw Materials

(1) Ethylene•α-olefin Random Copolymer Rubber

An oil-extended ethylene•α-olefin random copolymer containing, in aweight ratio of 50/50, an ethylene/propylene/5-ethylidene-2-norborneneternary copolymer rubber (a11), ethylene content: 66 weight %,5-ethylidene-2-norbornene content: 4.5 weight %, a limiting viscosity[η] measured at 135° C. in decaline: 4.7 dl/g, and a mineral oil typesoftening agent (trade name Diana Process Oil PW-380, manufactured byIdemitsu Kosan Co., Ltd.);

(2) Olefinic Resin

1) Crystalline olefinic resin (b13): a propylene/ethylene randomcopolymer, density: 0.90 g/cm³, MFR (temperature 230° C., load 2.16kgs): 23 g/10 minutes, (trade name Novatec PP FL25R, manufactured byNippon Polychem Co.);

2) Amorphous olefinic resin (b2): a propylene/1-butene amorphouscopolymer; propylene content: 71 mol %, melt viscosity: 8 Pa·s, density:0.87 g/cm³, Mn: 6500, (trade name APAO UT2780, manufactured by UbeIndustries Ltd.);

(3) (Meth)acrylate Resin:

a methyl methacrylate/methyl acrylate copolymer (c1); density: 1.19g/cm³, MFR (temperature 230° C., load 3.8 kgs): 8 g/10 minutes, (tradename Parapet G, manufactured by Kuraray Ltd.);

(4) Hydrogenated Diene Polymer (d1)

A hydrogenated diene polymer was synthesized by a following method. Alsomeasurements were made by following methods:

1) vinyl aromatic compound content: measured by an infrared analysisbased on a phenyl group absorption at 679 cm⁻¹;

2) vinyl bond content of conjugate diene: calculated by Morello methodbased on infrared analysis;

3) hydrogenation rate: calculated from ¹H-NMR spectrum at 90 MHzemploying carbon tetrachloride as a solvent;

4) weight average molecular weight: calculated by polystyreneconversion, utilizing gel permeation chromatography (GPC) at 38° C.,utilizing tetrahydrofuran as a solvent.

Method of Synthesis of Hydrogenated Diene Polymer

In an autoclave with an internal volume of 5 liters, 2.5 kgs ofcyclohexane, 15 g of tetrahydrofuran, 110 g of styrene (block Acomponent), and 0.55 g of n-butyl lithium were charged and polymerizedat 50° C. to a conversion yield of 98% or higher. Then 220 g of1,3-butadiene (block B component) were added and polymerized to aconversion yield of 98% or higher, and 110 g of styrene (block Acomponent) were further added and polymerized to a conversion yield of100%.

After the completion of the polymerization, the reaction liquid wasmaintained at 70° C., 0.33 g of n-butyl lithium, 0.61 g oft-hydroxy-4-methyl-2-pentanone, 0.21 g of bis (cyclopentadienyl)titanium dichloride and 0.76 g of diethyl aluminum chloride were addedand reacted for 1 hour at a hydrogen pressure of 10 kg/cm² to achievehydrogenation. The reaction liquid was charged and mixed in a largeamount of methyl alcohol, and a precipitated solid was recovered anddried to obtain a block copolymer. This hydrogenated diene polymer (d1)was of A-B-A type, and had a hydrogenation rate of 95%, a 1,2-vinyl bondcontent in the butadiene unit of the block B of 80%, a mass ratio ofblock A/block B of 50/50 and a weight average molecular weight of100,000.

(5) Crosslinking Agent

1) Organic peroxide (h1): 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane(trade name Perhexa 25B-40, manufactured by NOF Corp.);

2) Auxiliary crosslinking agent (i1): divinylbenzene (purity 55%),(manufactured by Sankyo Kasei Co.);

(6) Maleimide Compound (e1): N,N′-m-phenylenebis Maleimide (Trade NameVulnoc PM, Manufactured by Ouchishinko Chemical Industries Co., Ltd.)

(7) Other Additives

1) Antiaging agent (j1): trade name Irganox 1010 (manufactured by CibaSpecialty Chemicals Co.);

2) Silicone oil: polydimethylorganosiloxane, trade name SH-200(viscosity=100 cSt), manufactured by Toray Dow-Corning Silicone Co.

EXAMPLE 11

[2] Production of Maleimide Compound-containing Composition [C]

80 parts by mass of ethylene•α-olefin random copolymer rubber (a11), 15parts by mass of crystalline olefinic resin (b13), 5 parts by mass ofamorphous olefinic resin (b2), 0.5 parts by mass of maleimide compound(e1), and 0.1 parts by mass of antiaging agent (j1) were charged in adual-arm type pressurized kneader of a volume of 10 liters (manufacturedby Moriyama Company Ltd.) heated at 150° C. and kneaded for 20 minutesat 40 rpm. Then the composition in a melting state was pelletized with afeeder-ruder (manufactured by Moriyama Company Ltd.) set at 180° C. and40 rpm. The obtained pellets were added with 1 part by mass of anorganic peroxide (h2) and 0.2 parts by mass of a silicone oil (k1) andwere mixed for 30 seconds in a Henshel mixer. Then a two-shaft extruder(trade name PCM-45, manufactured by Ikegai Ltd., with completely meshingscrews in a same direction, L/D (ratio of a screw flight length L andscrew diameter D)=33.5) was used to execute an extrusion by dynamicallyheat-treating under conditions of 230° C., 300 rpm and a retention timeof 2 minutes, thereby producing a maleimide-containing composition [C],which was a pellet-shaped dynamically crosslinked thermoplasticelastomer composition.

[3] Preparation of Test Piece of Maleimide Compound-containingComposition [C]

Pellets of the obtained maleimide compound-containing composition [C]were injection molded with an injection molding machine (trade nameN-100, manufactured by Japan Steel Work Co.) to obtain a sheet of athickness of 2 mm, a length of 120 mm and a width of 120 mm, which wasused for various evaluations.

[4] Evaluation of the Maleimide Compound-containing Composition [C]

-   (1) fluidity: a melt flow rate was measured at 230° C. and under a    load of 10 kg as an index of fluidity;-   (2) hardness: measured according to JIS K 6253 as an index of    flexibility;-   (3) tensile strength at break and tensile elongation at break:    measured according to JIS K 6251;-   (4) permanent compression set: measured according to JIS K 6262 as    an index of rubber elasticity and under conditions of 70° C. and 22    hours;-   (5) injection fusibility: A test piece prepared by injection fusing    a maleimide compound-containing composition [C] to a test piece of    an olefinic vulcanized rubber was bent by 180° at a junction of the    maleimide compound-containing composition [C] and the member for    adhesion, and a peeling state at the adhering interface after    repeating the bending 10 times was observed visually.

Criteria for evaluation were as follows: ◯: no peeling, Δ: partialpeeling, X: peeling leading to breaking.

1) Preparation of a Member for Adhesion

A following olefinic vulcanized rubber sheet was prepared as a memberfor adhesion and used for testing.

In 100 parts by mass of an ethylene/propylene/5-ethylidene-2-norborneneternary copolymer rubber (ethylene content: 72 mol %, propylene content:28 mol %, Mooney's viscosity: 92, iodine value: 15, trade name EP 103A,manufactured by JSR Corp.), 145 parts by mass of carbon black (tradename Seast 116, manufactured by Tokai Carbon Co.), 85 parts by mass of amineral oil type softening agent (g1) (trade name Diana Process OilPW380, manufactured by Idemitsu Kosan Co., Ltd.), 5 parts by mass ofzinc white (manufactured by Sakai Chemical Industry Co.), 1 part by massof stearic acid (manufactured by Asahi Denka Corp.), 1 part by mass ofan auxiliary work agent (trade name Hitanol 1501, manufactured byHitachi Chemical Co.), 2 parts by mass of a release agent (trade nameStructol WB212, manufactured by Syl and Zilaher Co.), and 1 part by massof a plasticizer (polyethylene glycol) were kneaded in a Banbury mixerof a capacity of 3 liters (manufactured by Kobe Steel Ltd.) underconditions of 50° C., 70 rpm and a time of 2.5 minutes. Thereafter, 10parts by mass of a dehydrating agent (trade name Vesta PP, manufacturedby Inoue Sekkai Kogyo Co.), vulcanization accelerators (M (trade name)by 1 part by mass, PX (trade name) by 1 part by mass, TT (trade name) by0.5 parts by mass and D (trade name) by 1 part by mass, all manufacturedby Ouchishinko Chemical Industries Co., Ltd.) and 2.2 parts by mass ofsulfur were added and kneaded at 50° C. with 6-inch open rolls(manufactured by Kansai Roll Co.). The vulcanization was conducted for10 minutes at 170° C. to obtain an olefinic vulcanized rubber sheet of asquare of 120 mm and a thickness of 2 mm. The sheet was punched with adumbbell cutter into a length of 60 mm and a width of 50 mm to prepare amember for adhesion.

2) Preparation of a Test Piece by Injection Fusion of ThermoplasticElastomer to Olefinic Vulcanized Rubber

In a split mold (having a test piece shape of 120×120×2 mm) of aninjection molding machine (type N-100, manufactured by Japan Steel WorkCo.), the aforementioned member for adhesion (60×50×2 mm) was placed inadvance, and each obtained thermoplastic elastomer composition wasinjection molded on the member for adhesion to obtain a square plate(120×120×2 mm) in which the thermoplastic elastomer composition and theolefinic vulcanized rubber (member for adhesion) were fused.

-   (6) scratch resistance tests 1) and 2): Tests were made in the same    manner as explained in the foregoing. Criteria for evaluation were    also same.

The results of these evaluations are shown in Tables 3 and 4.

EXAMPLES 12-18 AND COMPARATIVE EXAMPLES 11-15

The pellet-shaped maleimide compound-containing compositions [C] andtest pieces were prepared in the same manner as in Example 11, withformulations as shown in Tables 3 and 4. The maleimidecompound-containing compositions [C] were evaluated in a similar manner.The results of evaluations of the maleimide compound-containingcomposition [C] are shown in Tables 3 and 4.

TABLE 3 Example Comparative Example 11 12 13 14 15 11 12 13 formulationoil-extended EPDM (all) (mineral oil softening agent 80(40) 80(40)70(35) 75(37.5) 65(32.5) 80(40) 80(40) 80(40) content 50 mass %)crystalline olefinic resin (b13) 15 15 25 20 10 15 15 15 amorphousolefinic resin (b2) 5 5 5 5 10 5 5 5 maleimide compound (e1) 0.5 0.5 0.51 0.5 — 0.25 — maleimide compound content (mass part) with sum of 0.50.5 0.5 1 0.5 — 0.25 — rubber, olefinic resin and softening agent takenas 100 mass parts post-addition mineral oil (g1) — — — — 15 — — —softening agent content (mass %) with sum EPDM 40 40 35 37.5 32.5 40 4040 of rubber, olefinic total olefinic resin 20 20 30 25 20 20 20 20resin, and softening mineral oil softening 40 40 35 37.5 47.5 40 40 40agent taken as 100 mass % agent crosslinking agent (h1) 1 1 1 1 1 1 1 1auxiliary crosslinking (h3) — — — — — — — 1.25 agent antiaging agent(j1) 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 silicone oil (k1) 0.2 0.2 0.2 0.20.2 0.2 0.2 0.2 physical fluidity MFR(230° C. × 5 kg)[g/ 101 106 120 110102 52 80 42 properties 10 min] mechanical properties hardness (type A67 65 8.6 78 49 67 68 57 durometer) tensile strength at break 6.5 6.29.7 8 3.5 5 6 8.8 [MPa] tensile elongation 740 570 680 640 660 810 780720 at break (%) permanent compression set CS(70° C. × 22 hr)[%] 50 4759 49 61 65 57 45 injection fusibility 180° bending peel ◯ ◯ ◯ ◯ ◯ X X X[visual inspection] Parenthesized number in oil-extended EPDM columnindicates EPDM content (parts by mass).

TABLE 4 Example Comp. Example 16 17 18 14 15 formulation oil-extendedEPDM (all) (mineral 70(35) 80(40) 64(32) 70(35) 70(35) oil softeningagent content 50 mass %) crystalline olefinic resin (b13) 26 14 32 26 26amorphous olefinic resin (b2) 4 6 4 4 4 content (mass %) with sum ofEPDM 35 40 32 35 35 rubber, olefinic resin, and total olefinic resin 3020 36 30 30 softening agent taken as 100 mineral oil softening agent 3540 32 35 35 mass % maleimide compound (e1) 0.6 1.2 0.6 — — maleimidecompound content (mass part) 0.6 1.2 0.6 — — with sum of rubber,olefinic resin and softening agent as 100 mass parts (meth)acrylateresin (c1) 12 12 12 12 12 (meth)acrylate resin content (mass part) 12 1212 12 12 with sum of rubber, olefinic resin and softening agent as 100mass parts hydrogenated diene polymer (d1)   6(0.5)   6(0.5)   6(0.5)  6(0.5)   6(0.5) crosslinking agent (h1) 1.2 1.2 1.2 — 1.2 auxiliarycrosslinking agent (h3) — — — — 1.5 antiaging agent (j1) 0.12 0.12 0.120.12 0.12 silicone oil (k1) 0.24 0.24 0.24 0.24 0.24 physical propertiesfluidity MFR(230° C. × 5 kg)[g/10 min] 35 5 45 3 16 mechanicalproperties hardness (type A durometer) 88 70 92 89 88 tensile strengthat break [MPa] 7.4 5.8 8 7.2 8 tensile elongation at break (%) 850 730600 1120 720 permanent compression set CS(70° C. × 22 hr)[%] 59 55 66 8856 injection fusibility 180° bending peel [visual ◯ ◯ ◯ X X inspection]scratch resistance (1) 50 40 50 10 or less 50 scratch resistance (2) ◯ ◯◯ X ◯ Parenthesized number in oil-extended EPDM column indicates EPDMcontent (parts by mass). Also parenthesized number in hydrogenated dienepolymer column indicates a mass ratio to (meth)acrylate resin.(6) Result of Example

Table 3 indicates that Examples 11 to 15 are excellent in the mechanicalproperties, the rubber elasticity and the injection fusibility.Comparative Examples 11 and 12 are inferior in the workability, themechanical properties, the rubber elasticity and the injectionfusibility because the addition amount of the maleimide compound isoutside the range of the invention. Comparative Example 13 is inferiorin the injection fusibility because of use of an auxiliary crosslinkingagent other than the maleimide compound. Also Table 4 indicates thatExamples 16 to 18 are excellent in the scratch resistance, themechanical properties, the rubber elasticity and the injectionfusibility. Comparative Example 14 is inferior in the mechanicalproperties, the rubber elasticity, the scratch resistance and theinjection fusibility because of absence of crosslinking. AlsoComparative Example 15 is inferior in the injection fusibility becauseof use of an auxiliary crosslinking agent other than the maleimidecompound.

4. Examples on Polysiloxane-containing Composition [D]

Rubber, crystalline olefinic resin, amorphous olefinic resin, softeningagent, crosslinking agent or the like. employed as raw materials were asfollows.

[1] Raw Materials

(1) Oil-extended Rubber

1) oil-extended rubber (a11): anethylene/propylene/5-ethylidene-2-norbornene ternary copolymer rubber,ethylene content: 66 mass %, 5-ethylidene-2-norbornene content: 4.5 mass%, a limiting viscosity measured at 135° C. in decaline: 4.7 dl/g, amineral oil type softening agent (trade name Diana Process Oil PW-380,manufactured by Idemitsu Kosan Co., Ltd.) content 50 mass %;

2) oil-extended rubber (a12): anethylene/propylene/5-ethylidene-2-norbornene ternary copolymer rubber,ethylene content: 66 mass %, 5-ethylidene-2-norbornene content: 4.5 mass%, a limiting viscosity measured at 135° C. in decaline: 3.8 dl/g, amineral oil type softening agent (trade name Diana Process Oil PW-380,manufactured by Idemitsu Kosan Co., Ltd.) content 40 mass %;

(2) Olefinic Resin

1) propylene/ethylene random copolymer (b3), density: 0.90 g/cm³, MFR(temperature 230° C., load 2.16 kgs): 23 g/10 minutes, (trade nameNovatec PP FL25R, manufactured by Nippon Polychem Co.);

2) propylene/1-butene amorphous copolymer (b2); propylene content: 71mol %, melt viscosity: 8 Pa·s, density: 0.879 g/cm³, Mn: 6500, (tradename APAO UT2780, manufactured by Ube Industries Ltd.);

(3) Undenatured Organopolysiloxane

1) polydimethylsiloxane (f11): viscosity 100 cSt (trade name SiliconeOil SH-200, manufactured by Toray Dow-Corning Silicone Co.);

2) polydimethylsiloxane (f12): viscosity 1,000 cSt (trade name SiliconeOil SH-200, manufactured by Toray Dow-Corning Silicone Co.);

3) polydimethylsiloxane (f13): viscosity 5,000 cSt (trade name SiliconeOil SH-200, manufactured by Toray Dow-Corning Silicone Co.);

4) polydimethylsiloxane (f14): viscosity 12,500 cSt (trade name SiliconeOil SH-200, manufactured by Toray Dow-Corning Silicone Co.);

5) ultra-high molecular weight silicone rubber (f15): viscosity1,000,000 cSt or higher (trade name BY16-140, manufactured by TorayDow-Corning Silicone Co.);

(4) Denatured Organopolysiloxane

-   -   acryl-denatured silicone resin (f2): trade name x-22-8171,        manufactured by Shin-Etsu Chemical Co., Ltd.;

-   (5) Mineral Oil Type Softening Agent (g1): Trade Name Diana Process    Oil PW-380, Manufactured by Idemitsu Kosan Co., Ltd.;

-   (6) Crosslinking Agent and Auxiliary Crosslinking Agent

1) 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane (h1): trade name Perhexa25B-40, manufactured by NOF Corp.);

2) N,N′-m-phenyleneb is maleimide (h2): trade name Vulnoc PM,manufactured by Ouchishinko Chemical Industries Co., Ltd.)

3) auxiliary crosslinking agent (h3): divinylbenzene (manufactured bySankyo Kasei Co.);

-   (6) Antiaging Agent (j1): Trade Name Irganox 1010, Manufactured by    Ciba Specialty Chemicals Co.    [2] Production of Polysiloxane-containing Composition [D]

EXAMPLES 19-25 AND COMPARATIVE EXAMPLES 16-20 (PRODUCTION BY CLOSEDKNEADER+CONTINUOUS KNEADER)

A raw material composition of a formulation shown in Tables 5 and 6excluding a crosslinking agent was charged in a pressurized kneader(manufactured by Moriyama Company Ltd.) heated to 150° C., and waskneaded for 15 minutes at 40 rpm until the components were uniformlydispersed. Then the composition in a melting state was pelletized with afeeder-ruder (manufactured by Moriyama Company Ltd.). The obtainedpellets were added with a crosslinking agent and an auxiliarycrosslinking agent in a formulation shown in Tables 5 and 6 and weremixed for 30 seconds in a Henshel mixer. Then the mixture was suppliedby a weight type feeder with a discharge amount of 40 kg/hr to atwo-shaft extruder (non-meshing screws in a same direction, L/D=38.5,tradename PCM-45, manufactured by Ikegai Ltd.) and was extruded underdynamically heat-treating at 200° C., a screw revolution of 300 rpm anda retention time of 2 minutes to produce a polysiloxane-containingcomposition [D], as a dynamically crosslinked thermoplastic elastomercomposition.

[3] Evaluation of Polysiloxane-containing Composition [D]

Following items were measured in order to evaluate the obtainedpolysiloxane-containing compositions [D]:

1) melt flow rate (MFR): measured at 230° C. and a load of 10 kg;

2) hardness, tensile strength at break and tensile elongation at break:measured according to JIS K 6301;

3) permanent compression set: measured according to JIS K 6301, underconditions of 70° C., 22 hours and 25% compression;

4) initial slidability and durable slidability

A reciprocating sliding tester (manufactured by Tosoku Seimitsu Co.) wasused, under a load of 233 g/3 cm² (planar pressure 78 g/cm²) and asliding speed of a glass ring test piece of 100 mm/min (with a stroke of50 mm) to measure a static friction coefficient and a dynamic frictioncoefficient of a test piece (length 110 mm, width 61 mm and thickness 2mm) of the polysiloxane-containing compositions [D] to a cylindricalglass ring test piece of an external diameter of 25.7 mm, an internaldiameter of 20 mm, a height of 16.5 mm and a weight of 9.6 g. An initialslidability was measured at the room temperature on a test piece after 1day from injection molding. Also a durable slidability was measured atthe room temperature on a test piece which was let to stand in a gearoven of 100° C. for 500 hours after injection molding.

5) bleeding test: A test piece constituted of thepolysiloxane-containing composition [D] was let to stand for 120 hoursin a gear oven (manufactured by Toyo Seiki Co.) of 100° C., and asurface state of the test piece was visually observed.

6) Extrusion workability: A laboplast mill extruder (manufactured byToyo Seiki Co., external diameter=20 mm, L/D=25) was used to extrude aslab (lipwidth: 25 mm, thickness: 1.5 mm) in the following conditionsand an external appearance was visually evaluated. A case with a smoothsurface and an edge was evaluated as “◯”, and any other case wasevaluated as “X”:

-   -   cylinder C1=180° C., cylinder C2=190° C., cylinder C3=210° C.,        die=205° C., screw revolution=40 rpm.

7) Injection fusibility: A test piece prepared by injection fusing apolysiloxane-containing composition [D] was bent by 180° at a junctionof the polysiloxane-containing composition [D] and a member foradhesion, and a peeling state at the adhering interface was observedvisually.

Criteria for evaluation were as follows: ◯: no peeling, Δ: partialpeeling, X: peeling leading to breaking.

For the aforementioned evaluations 2) to 5), a test piece of a size of120×120×2 mm was prepared by injection molding thepolysiloxane-containing composition [D] by an injection molder (tradename: N-100, manufactured by Japan Steel Work Co.).

[4] Preparation of a Member for Adhesion

For the aforementioned 7), a member for adhesion of an olefinicvulcanized rubber was prepared in the following manner and used fortesting.

In 100 parts by mass of an ethylene/propylene/5-ethylidene-2-norborneneternary copolymer rubber (ethylene content: 72 mol %, propylene content:28 mol %, Mooney's viscosity: 92, iodine value: 15, trade name EP 103A,manufactured by JSR Corp.), 145 parts by mass of carbon black (tradename Seast 116, manufactured by Tokai Carbon Co.), 85 parts by mass of amineral oil type softening agent (g1) (trade name Diana Process OilPW380, manufactured by Idemitsu Kosan Co., Ltd.), 5 parts by mass ofzinc white (manufactured by Sakai Chemical Industry Co.), 1 part by massof stearic acid (manufactured by Asahi Denka Corp.), 1 part by mass ofan auxiliary work agent (trade name Hitanol 1501, manufactured byHitachi Chemical Co.), 2 parts by mass of a release agent (trade nameStructol WB212, manufactured by Syl and Zilaher Co.), and 1 part by massof a plasticizer (polyethylene glycol) were blended to obtain a mixture.

Then the mixture was kneaded in a Banbury mixer under conditions of 50°C., 70 rpm and a time of 2.5 minutes. Thereafter, 10 parts by mass of adehydrating agent (trade name Vesta PP, manufactured by Inoue SekkaiKogyo Co.), vulcanization accelerators (M (trade name) by 1 part bymass, PX (trade name) by 1 part by mass, TT (trade name) by 0.5 parts bymass and D (trade name) by 1 part by mass, all manufactured byOuchishinko Chemical Industries Co., Ltd.) and 2.2 parts of sulfur wereadded and kneaded at 50° C. with open rolls. Then a vulcanization wasconducted for 10 minutes at 170° C. to obtain an olefinic vulcanizedrubber sheet of a square of 120 mm and a thickness of 2 mm. The sheetwas punched with a dumbbell cutter into a length of 60 mm and a width of50 mm to prepare a member for adhesion.

[5] Preparation of a Test Piece by Injection Fusion of ThermoplasticElastomer to Olefinic Vulcanized Rubber

In a split mold (having a test piece shape of 120×120×2 mm) of aninjection molding machine (type N-100, manufactured by Japan Steel WorkCo.), the aforementioned member for adhesion (60×50×2 mm) was placed inadvance, and each obtained thermoplastic elastomer composition wasinjection molded on the member for adhesion to obtain a square plate(120×120×2 mm) in which the thermoplastic elastomer composition and theolefinic vulcanized rubber were fused.

The results of these evaluations are shown in Tables 5 and 6.

TABLE 5 limiting mineral oil type viscosity softening agent contentExample oil-extended rubber (dl/g) (mass %) 19 20 21 22 23 24 25oil-extended EPDM (a11) 4.7 50 30 32.5 40 70 70 70 70 oil-extended EPDM(a12) 3.8 40 30 32.5 40 — — — — content (mass %) with sum of EPDM EPDM45 45 55 50 50 50 50 and softening agent in oil- mineral oil softening55 55 45 50 30 50 50 extended rubber as 100 mass % agent crystallineolefinic resin (b13) 5 5 7.5 25 25 30 30 amorphous olefinic resin (b2) 55 7.5 5 5 — — post-addition mineral oil softening agent (g1) 25 15 5 — —— — content (mass part) with sum of oil-extended EPDM 63.2 72.2 80 70 7070 70 oil-extended rubber, olefinic total olefinic resins 10.5 11.1 1530 30 30 30 resin and post-addition post-addition softening 26.3 16.7 5— — — — softening agent as 100 mass agent parts low-viscosity viscosity100 cSt (f11) — — — — 0.5 — 0.5 undenatured viscosity 1,000 cSt (f12) —3 3 1.5 — 1.5 — organopolysiloxane viscosity 5,000 cSt (f13) 1.5 — — — —— — high-viscosity viscosity 12,500 cSt (f14) 1.5 3 3 1.5 — 1.5 —undenatured viscosity 1,000,000 cSt (f15) — — — — 2.5 — 2.5organopolysiloxane acryl-denatured organopolysiloxane (f2) 1 1 1 1 0.5 10.5 content (mass part) with sum of low-viscosity undenatured 1.6 3.7 31.5 0.5 1.5 0.5 oil-extended rubber, olefinic organopolysiloxane resinand post-addition high-viscosity undenatured 1.6 3.7 3 1.5 2.5 1.5 2.5softening agent as 100 mass organopolysiloxane parts acryl-denatured 1.11.1 1 1 0.5 1 0.5 organopolysiloxane crosslinking agent (h1) 1 1 1 0.50.5 0.5 0.5 crosslinking agent (h2) — — — 1 1 1 1 auxiliary crosslinkingagent (h3) 1.3 1.3 1.3 — — — — antiaging agent (j1) 0.1 0.1 0.1 0.1 0.10.1 0.1 MFR (g/10 min) 330 520 280 300 285 285 270 Hardness [JIS-Ahardness] 42 41 51 85 87 87 87 tensile strength at break (MPa) 3.9 3.74.6 10 9.8 9.8 10.1 tensile elongation at break (%) 800 770 760 740 710710 720 permanent compression set (%) 42 43 46 59 60 60 60 initialslidability static friction coefficient 0.61 0.45 0.32 0.29 0.3 0.450.31 dynamic friction coefficient 0.63 0.38 0.29 0.25 0.26 0.34 0.28durable slidability static friction coefficient 0.57 0.52 0.62 0.3 0.350.52 0.36 dynamic friction coefficient 0.57 0.35 0.25 0.28 0.3 0.43 0.32bleeding test (◯: absent, X: present) ◯ ◯ ◯ ◯ ◯ ◯ ◯ extrusionworkability ◯ ◯ ◯ ◯ ◯ ◯ ◯ injection fusibility ◯ ◯ ◯ ◯ ◯ ◯ ◯

TABLE 6 limiting mineral oil type viscosity softening agent ComparativeExample oil-extended rubber (dl/g) content (mass %) 16 17 18 19 20oil-extended EPDM (a11) 4.7 50 32.5 32.5 32.5 32.5 32.5 oil-extendedEPDM (a12) 3.8 40 32.5 32.5 32.5 32.5 32.5 content (mass %) with sum ofEPDM 45 45 45 45 45 EPDM and softening agent in mineral oil 55 55 55 5555 oil-extended rubber as 100 softening agent mass % crystallineolefinic resin (b13) 5 5 5 5 5 amorphous olefinic resin (b2) 5 5 5 5 5post-addition mineral oil softening agent (g1) 15 15 15 15 15 content(mass part) with sum of oil-extended EPDM 72.2 72.2 72.2 72.2 72.2oil-extended rubber, olefinic total olefinic resins 11.1 11.1 11.1 11.111.1 resin and post-addition softening post-addition 16.7 16.7 16.7 16.716.7 agent as 100 mass parts softening agent low-viscosity viscosity 100cSt (f11) 3 — — — — undenatured viscosity 1,000 cSt (f12) — 3 — — 3organopolysiloxane viscosity 5,000 cSt (f13) — — 3 — — high-viscosityviscosity 12,500 cSt (f14) — — — 3 3 undenatured viscosity 1,000,000 cSt(f15) — — — — — organopolysiloxane acryl-denatured organopolysiloxane(f2) — — — — — content (mass part) with sum of low-viscosity 3.3 3.3 3.3— 3.3 oil-extended rubber, olefinic undenatured resin and post-additionsoftening organopolysiloxane agent as 100 mass parts high-viscosity — —— 3.3 3.3 udenatured organopolysiloxane acryl-denatured — — — — —organopolysiloxane crosslinking agent (h1) 1 1 1 1 1 crosslinking agent(h2) — — — — — auxiliary crosslinking agent (h3) 1.3 1.3 1.3 1.3 1.3antiaging agent (j1) 0.1 0.1 0.1 0.1 0.1 MFR (g/10 min) 200 130 290 250280 Hardness [JIS-A hardness] 43 43 42 42 42 tensile strength at break(MPa) 4 3.9 4.2 4.1 3.7 tensile elongation at break (%) 760 760 780 770680 permanent compression set (%) 39 40 43 45 43 initial slidabilitystatic friction coefficient 0.55 0.81 0.93 0.97 0.6 dynamic frictioncoefficient 0.53 0.67 0.72 0.7 0.59 durable slidability static frictioncoefficient 1.5 1.48 1.16 0.88 1.25 dynamic friction coefficient 1.1 10.73 0.69 1.1 bleeding test (◯: absent, X: present) X X X ◯ X extrusionworkability ◯ ◯ ◯ ◯ X injection fusibility ◯ ◯ ◯ ◯ X(6) Result of Example

According to Tables 5 and 6, Comparative Examples 16 to 18 employed alow-viscosity undenatured organopolysiloxane only and did not employ anacryl-denatured organopolysiloxane. For this reason, they were excellentin the extrusion workability and the injection fusibility, but wereinferior in the initial and durable slidability, and a bleeding wasconfirmed. A comparative Example 19 employed a high-viscosityundenatured organopolysiloxane only but did not employ anacryl-denatured organopolysiloxane. For this reason, it was excellent inthe extrusion workability and the injection fusibility, but was inferiorin the initial and durable slidability. Also a comparative Example 20employed high-viscosity and low-viscosity undenaturedorganopolysiloxanes but did not employ an acryl-denaturedorganopolysiloxane. For this reason, it was inferior in the initial anddurable slidability, the extrusion workability and the injectionfusibility, and a bleeding was also confirmed. On the other hand,polysiloxane-containing compositions [D] of Examples 19 to 25 wereexcellent in the initial and durable slidability and the extrusionworkability, and did not show the bleeding of organopolysiloxane. Alsothere were not observed a peeling or a breakage, and an excellenginjection fusibility was identified.

1. A thermoplastic elastomer composition prepared by a process whichcomprises: dynamically heat treating, in the presence of a crosslinkingagent, a polymer composition comprising a rubber, an olefinic resinmixture comprising at least one crystalline olefinic resin and at leastone amorphous olefinic resin, a softening agent, a (meth)acrylate resin,and a maleimide compound, wherein for the sum of said rubber, saidolefinic resin mixture and said softening agent taken as 100 parts bymass, said maleimide compound is present at a level of 0.3 to 10 partsby mass and said (meth)acrylate resin is present at a level of 1 to 30parts by mass.
 2. The thermoplastic elastomer composition according toclaim 1, wherein said polymer composition further comprises ahydrogenated diene polymer, wherein said hydrogenated diene polymer ispresent at a level of 0.1 to 1 in a mass ratio to said (meth)acrylateresin.
 3. The thermoplastic elastomer composition according to claim 1,wherein the at least one crystalline olefinic resin comprises anα-olefin as a principal constituent unit in an amount of 80 mol % ormore, based on total crystalline olefinic resin.
 4. The thermoplasticelastomer composition according to claim 1, wherein the at least onecrystalline olefinic resin has a crystallinity of 50% or higher, asmeasured by X-ray diffraction.
 5. The thermoplastic elastomercomposition according to claim 1, wherein the at least one amorphousolefinic resin comprises an α-olefin as a principal constituent unit inan amount of 50 mol % or more, based on total amorphous olefinic resin.